I'd also like to note that for people creating content on the web, especially programming-type people who deal in logic and certainty, the SEO system resembles something like black magic. It's pretty clear that unless you understand SEO and apply it, you're never going to be seen no matter how good your content is. Now it appears that if you understand it too well that's also a bad thing.
The goal here is to let the users themselves inform the search engine as to what content is good -- hence the plus-ones, social search and all of that stuff. But all of this is still indirect evidence. Unless you could plug a computer inside the head of a person and watch their every thought, the only real data you have for input is server logs, click-throughs, and all kinds of other things that computers do, not people.
I just don't see this being solved any time soon. But I do see it getting so complex and unwieldy that it continues to frustrate searchers and content producers alike. Meanwhile the bad actors will continue to have a heyday.
Wish I could be more optimistic about it.