IMO, this latter usage is consistent with both HTML 4 and HTML5 semantics. I suppose Google's approach can be read as consistent with the specs, too, but either usage takes a different interpretation of "a document" and the relationships in a series of documents.
The Google article talks mainly about paginated content and mentions that it comes in different forms. The examples given in the article suggest that here we have a sequence of pages where we should or could have only one document, like in the example of the forum thread: it may consist of many pages, ordered in a linear fashion, but individual pages of the thread might be somehow incomplete. The whole thread is the document. I think that this interpretation is different from the interpretation of next/prev indicating a chronologically ordered sequence.
The article mentions also "The first page":
>>The first page only contains rel=”next” and no rel=”prev” markup.<<
"The first page" means that there is only one. Could we have more than one first page as entry point into the sequence? Like a story with different possible beginnings converging to a common end?
And Firefox will pre-fetch links with rel="next" so that they load faster: https://developer.mozilla.org/en/Link_prefetching_FAQ
Ironically, HTML5 recently dropped bunch of link relationships because of lack of browser and search engine support.
Hopefully this catches on, and we can use this instead of every site trying to have its own keyboard shortcuts (j/k or left/right or z/x/c, that last one being especially stupid for non-qwerty typists).
The flip side of this is that publishers are now offering an inferior experience to users who navigate directly to their sites. If I type in NYTimes.com and start browsing through articles because I'm a big fan of The New York Times, I'm treated worse (I have to deal with an article limit and pagination) than if I stumble on their articles through Google. Google is giving more and more value to brands, while creating an atmosphere that rewards people who have no brand loyalty (except to Google).
Google has been strong-arming publishers for a long time. Generally it has made the Internet a better place, but it still makes me nervous (especially as a publisher). Google seems to be pushing to eliminate more and more tactics that are profitable for publishers (and generally bad for users). I doubt that Google will kill the goose that laid the golden egg, but you have to think that publishers are going to start to push back if it goes much further.
They could be utilizing their search dominance to do a lot more harm than good. However, almost everything they do helps make the web better, even if it does push their bottom line. That's business.
Most businesses don't care about your loyalty to other brands. Why should they? Google, on the other hand, has made a lot of strides toward giving big brands benefits in the search results. I'm not sure whether this is good or bad, but saying they reward people who have no brand loyalty is untrue.
what i found was that opera started doing a pre-fetch on them as soon as i added the tags, so every time an opera user would visit the site, they would fetch two pages. i had to remove the tags to cut down on the resource usage.
There used to be proxies (Google Web Accelerator http://webaccelerator.google.com/support.html#basics2) that aggresively prefetched pages, but modern browsers don't prefetch unless you explicitly ask with rel=prefetch (or Chrome's own version of thereof).
If you aren't using infinite scrolling, chances are you're doing it wrong.