The first (and probably most useful) treats the blog as something like a diary: commentary on current events at some scale, e.g. personal, professional, news, et cetera. In this case, older content really does have much less relevance because the events themselves now live in the past. Your friends /might/ care about what you drank last night, but they almost certainly don't care about 5 months 12 days ago. You might want to comment on Linus' latest mailing list screed, but it might not matter for kernel-dabbling four years down the road.
The second use case seems to be where Daniel Tenner really is chewing on something. If you're writing new stuff that doesn't necessarily live in the moment - musings on philosophy or cool data structures or life advice or Paul Graham's articles - then the blog model doesn't fit as well. Newer posts don't matter more than older posts, and in fact might matter less.
Thinking on this, we also have the issue of serendipity. The writer has probably created other stuff that you might like reading even if it's not directly about the exact same topic. Seems like the sort of thing attacked by collaborative filtering and other methods. Combine that with a CMS-style knowledge architecture (e.g. structure by something other than chronology if chronology doesn't make sense), and you're getting somewhere.
The article you really should read is often not the one you're looking for. A system that makes it too easy to find what you think you need might paradoxically make it harder to stumble onto what you actually needed.
I also think that almost every great blogger who starts with the first use case ends up posting numerous timeless gems that get lost in the diary format. DaringFireball is, again, the obvious example.
Another thing that devalues blog content, where the same ideas and prose would be more valuable in another venue, is that they present pieces as inherently incomplete. Example: blog commenting, which encourage readers to see pieces not as fully developed ideas but simply as fodder for a conversation. That's great when a conversation is really what you wanted, but it's terrible when it results in your work being scored by the lowest common denominator of your comments.
Daring Fireball works because that's his job. It is the point of the site to be a carefully analyzed news bulletin.
But when you're (say) a software company with a product and, possibly as a result of that product, some interesting ideas about software, technology, products or what-have-you, a timely news bulletin is not your job, and if you're going to publish, you should do it in a way that optimizes the value of those ideas.
For our part, I'd like to reorganize and rewrite our blog posts into a book; start with a TOC, fill in the blanks with posts, let it be incomplete, and build it up over time. But I'd also like to get product shipped.
Since then, Patrick has discovered his bill rate, and I'm just speculating here but I'm guessing he's discovered that the value of being "of the linkerati", while palpable, is way way way below his bill rate, or the value of his work product when he builds scalable link generation systems.
But sometime around 2000-2003 or so, people just started throwing up everything on the equivalent of the "new articles" page! Seemed sort of a strange way to organize anything that wasn't a livejournal. Also seems to indicate a bit of a reduction in long-term ambition: people used to see building a website as an incremental endeavor, where you were slowly building up an edifice, so there was a clear separation between the long-term goal for the site (a resource w/ information presented logically) and the order in which you happened to add each piece (the recent-updates page).
Wikis still have that edifice-building angle (the "Recent Changes" page is clearly not the main page), so maybe it's just that they've taken over that role so completely that the only non-wiki things left are blogs and webapps, with no more "regular" websites?
Each of these sites emphasizes the now - to the extent that a 12 hour old story is old news. An entire story thread can surface and then disappear in a span of time that doesn't even last through the major global timezones (in Australia I often miss big stories because they are only up top for a matter of hours on US time)
So it isn't just the individual blogging model that needs to adapt, it is also the way aggregators and clients work. Everybody seems to be stuck focusing on what has happen in the past few hours.
A few years ago I wrote on Techcrunch about 'relevance over time' and how the blogs, twitter etc. need to adapt. None of the solutions have seemed to work, and all that means is that if you are a blogger and do not have a regular audience that checks your blog regularly, you are only going to get a decent number of readers for the odd post that surfaces its way up onto one of the large aggregators
I think that the new distributed social network will become the new blogging model - where you can pub and sub and not rely on aggregators that are tailored for a mass audience to find content. I am disappointed that all the new 'facebook alternative' projects are just about replacing or complementing facebook, rather than re-thinking the entire space of personal publishing. I miss the old blogosphere and would like to see it reborn in some way.
Edit: and as an example, I to manually tweet this comment. It doesn't appear on my blog, you can't reply to it from your own blog, and within 6 hours it will be long forgotten and we will have the same conversation again in 3 months time.
I checked out @swombat, and it's clear he's real, and not a bot, so having a bot sneak in a post back to past blog posts of value would hardly, if at all, be considered spam.
Some people get confused, particularly our friends who are just looking out for us, but a little blatant self-promotion is not always spam, and it's often times understood that it's a necessary evil so we can stay in business and keep doing the good we do.
The "essays" format or similar can do a decent job of funneling me towards timeless content once I am on a site looking for it (see Peter Norvig's webpage for another example), but it really doesn't address the stream issue.
Good luck with your tweeting experiment.
*I'm really thinking of something weaker than timelessness: worthwhile over a matter of years, at least.
- main page shows categories and a chronological list of posts (I don't post that often; if you do, maybe list the last 30-50 only ?) in the right sidebar
- each category gets an index-page with introduction and 3 articles highlighted, and a a list of all articles in the category in the left sidebar. The highlighted articles (new and old) should change every now and then, maybe somewhat depending on "the latest fads" ?
- most important (IMHO); go back to your old articles and update them, especially hyperlinks - this will also aid the discovery of "evergreen content"
In addition, you should probably also use tags (I don't, but that's just because I'm lazy and don't have that many articles).
You may also collect related articles in e-books (I've done it with one of the categories, but it is a lot of work) - less SEO value, but maybe more "reader value" ?
(personally, for blogs like swombats and pg, I often follow the timelines and read through the old stuff, bookmarking or saving the "golden nuggets" once and for all)
If you want to retweet your old articles, do it in a curated (i.e. human driven) way.
(WordPress has multiple plugins that can generate this automatically for you.)
Growing up, I used to love reading Mike Royko. He was sharp, and funny, and told the greatest stories in his newspaper column (A newspaper is a regularly scheduled publication containing news of current events, informative articles, diverse features and advertising. It usually is printed on relatively inexpensive, low-grade paper such as newsprint.)
And his columns (A column is a recurring piece or article in a newspaper, magazine or other publication. Columns are written by columnists.)
And then once a year, once every couple of years or so, he would collect his newspaper columns into a book.
And we would all go and buy his book.
At the beginning of blogging, I used to follow some bloggers that I thought were funny, and I would suggest they write their blogs in a way that would allow the blog to be collected into a book.
I thought by giving up a bit of the immediacy, by developing recurring characters (http://www.amazon.com/Slats-Grobnik-some-other-friends/dp/05...) that it would actually make their blogs more interesting, and give them a longer lasting character, than just a blog post that is mostly disappeared 10 posts later.
Sadly, Jeff Jarvis and others also thought of this, and then added cement galoshes to it by naming it a "blook". And that was the end of that.
But I hear what you are saying. Blogs are nice in that like a magazine they do emphasize content about a current event. Books are nice in that their organization adds a great deal of value to an otherwise random collection of unconnected essays. In that way, a book is an argument, (a connected series of statements intended to establish a proposition)
Blogs provide value to a socially connected world of twitter driven ADHD fanatics each seeking out the next shiny shiny source of poutrage.
But there has to be a more useful organization than just blogs, a calendar, and a google.
Perhaps if you thought about it as a book ahead of time, you could start out with a table of contents and a thesis, and use that mashed in with today's latest current event to focus what you blog about. And that would help you keep track and link from one post to another the way jwz does, or philg, or pg, or others.
Also, the standard blog format uses entire posts on the homepage and archive pages, but everything is so much cleaner and easier to navigate if only post summaries appear on those pages.
a) For new users: is this site any good?
b) For existing users (who don't grok RSS, sigh): is there anything new?
You can try to do more. Lots of us have category pages. But invariably they get browsed by initial visitors so they fall into category a above.
Perhaps what you're saying is that every website needs a channel to bring visitors back. And twitter may well be that channel. But bricestacey is right that the frontpage is all about user onboarding simply because nobody uses it for content discovery.
 Including myself: http://akkartik.name
I think that merely serving current/new users in this way is selling your content short. It's the written equivalent of a news channel, instead of being the evolution of the book. I'm hoping we can do better.
I'm not convinced that's true. The big limitation of the frontpage is that there's no way to remind people to return to it. Without that you'll only get current/new users.
I totally agree we need a solution for content discovery. Like many others I took my stab at building one (http://readwarp.com) I'm just not convinced that the frontpage is the place for it.
Bloggers should think of themselves as historians, taking their and others' content and putting it in a new context down the line when people have forgotten about it.
Wikis, imho, are a bit like search engines. They're great for collecting stuff that you want to find again, and they're great for finding stuff you're looking for. Blogs have something more - they point you to stuff which you never knew you could care about, they expand your interests. Wikis are a very clumsy substitute.
I think what's needed is perhaps an evolution of the blog format.