I think this comes down to the limitations of the algorithmically based search, and the power of mixing algorithm search and social user-user-website interaction.

If the engines can, as you suggest, start looking at HOW we work in our everyday lives (Google Desktop anyone?), seeing WHO we interact with, WHERE online we go, WHY we go there, WHEN we go there, and WHAT value we get from visiting those sites (information, community, inspiration), then we'll start seeing truly un-gamable search engines.

At that point, it ceases to become about having the right keyword density, or having great links, it's about having the right visitors. Which is down to having the right, relevant links, from the right places, and the right content, coupled with correct advertising and marketing to get the right people to your site.

A lot of variables to manage. And as I've been talking to other people about this, they seem to be agreeing with what I've been saying. And asking the next logical question:

What do I do to be ready for search 2.1?

The answer, of course, is simple. It's the same advise we've always given people: write great content, on theme.

Write the right content, and market well, and people will come, and then keep coming back.

To Pete: This might also be why Google released such a powerfull and free tool as Google Analytics is.

Imagine all that data at your/Googles fingertips... It must really produce invaluable information on cross site user behavior.

How does direct access figure into this? As a blogger, half of my visitors come directly to the site, often as word of mouth from another reader.

Can that be worked to increase authority/relevance in any way?

Personally I think that Editorial links will be devalued over time. Aaron is spot on about gaming the market. I think that keyword density is currently important with todays algo, but I think that time will soon pass. It's really just a matter of time before Google starts to group keywords in to specific sections. I do not know how many people have noticed, but Google has started to add about 10 additional keywords at the bottom of a search phrase for people to click on. They have to be doing it for a reason and my guess is to keep track of the click through's on it and see what grouping receives the most CTR so they can start to confirm things. Such as keyword1=keyword10 and keyword4 more than the rest and we should include that in the serps for keyword1. I have started to see more and more people saying that serps are beginning to show ranked pages that do not even have the keyword on page. Some have even said theere is no BL data that shows that anchor text either. Of course I am beginning to ramble on here :P

From a user perspective, however, a link is only as valuable as the content to which it links. If an SEO is able to create keyword specific copy that is very useful and readable, solid editorial linking, I believe, will still carry it's weight.

SEO writing 101: Start with good, user-friendly content, and everything else follows.

I don't think Google could ever change the effectiveness of that staple.

The number of RSS subscribers can be faked, IMO.

The rest is plausible, but not tangible enough to actually envision a move away from links-based rankings.

However, I think it's an excellent question and one that should be asked more and more.

Sure the number of RSS subscribers can be faked, but will the people faking that also be faking post reads on Google Reader? And natural related read profiles? And Google account history (including search and Gmail)?

I'm curious if/when the algorithms will be enhanced to start learning from user activity rather than just reporting on it. An example I can give: you have an online shopper that submits a credit card. It gets denied: stolen card. My code blocks that IP address for five minutes (can't block forever since they get recycled), the email address, and any other information I can tie to that transaction. If another transaction comes in within the next X-minutes with any of those same values, I then block any new associated information submitted (eg. same email, different credit card, different IP, etc. - all now blocked also) I continue to drill this person/process/server into the ground, making it next to impossible for them to game my system. Essentially any new data they submit to my system is only helping me further block more bad data - they will eventually give up and the data locks, over time, will be released.

The problem I have is that the white hats are continually abandoning solid ideas just to escape the black hats - those abusing the system. Instead of continually being reactive in nature, when will we be able to build on solid foundations rather than continually picking up camp and starting over?

.02

"... there are an increasing number of affordable marketing techniques that allow virtually any site to garner hundreds or thousands of quality links...."

Any suggested non Black-hat resources?

Some of the deductions seem too far fetched. Specially the bit about 'social media'. While i agree that people will lose interest in 'optimizing' (stuffing?) anchor text for a link and mostly generic terms will be used, 'optimizing' a link for traffic will always continue - unabated. I remember, way back in 1993 when i first started browsing the net, there was no Google, no Yahoo for me. Yet i found what i looked for because links were there! (and i clicked on better placed highlighted links more often, btw).

I don't think links will ever be completely discounted by the search engines. The only way they could do that is if they created an algorithm that was capable of reading pages and accurately judging their quality, relevance and usefulness. That kind of technology is still far off on the horizon.

Linguistic profiling is a very interesting concept, logical extension, but I must admit that I hadn't really thought about it before.

Especially in the case of the big G, I think digitizing tons of authoritative books will give them an incredible ruler to judge sites by.... if you have a source of credible writing on a subject, what better to judge future writing on? To some degree anyway.

Of course writing online is different than traditional print, and that may be exactly where this idea comes into play. It's more than just saying that "this" site which is a trusted authority is talking about some topic and using some keywords, therefore "that" site must be okay.... weighting in all the other metrics of authority of course.

But now you are adding in an entirely different metric... do they use the same language, similar style, discourse, all without tripping duplicate content filters.

After all, it is the perfect group theory.... those within a group are more likely to walk and talk and interact in similar manners. And after all, the web is nothing more than networked, grouped interactions, so why not apply traditional group theory, linguistic, and discourse analysis to all of the other metrics. Web anthropology... have to imagine it will be, if it isn't already, a major area of college study by 2010.

I love the idea of attention profiling. At least in terms of RSS readers. Email and IM mentions might raise privacy issues, but it would be really valuable if they would get around it.