Links are rapidly decreasing in importance and the general consensus amongst SEOs is that backlinks will soon follow in the footsteps of metatags i.e. some influence but certainly not worth trying to fiddle with. As a result, neither anchor texts not co-citation are worth putting much effort in for the sake of.
That does not mean you should not make every effort to stimulate organic links, as they do exactly what you want to happen: traffic coming to your site from people that have a genuine interest in the subject.
I agree that links do not carry as much weight as they use to, but only because the search engines continue to be more selective about which ones they count and how much weight they give. I think links and citations will continue to play a role in search engine rankings, but the search engines will become better at being able to identify and discount unnatural ones.
... the search engines will become better at being able to identify and discount unnatural ones.
That would be about 99% then.
Unnatural ones would be all that are:
exchanged via link wheels and the likes,
from blog farms and similar,
from sites owned my the same webmaster for no other reason than SEO purposes,
a number of other creative solutions.
"Natural" links i.e. those put up by unassociated third parties that do not benefit in any way, are very rare.
"Natural" links you meant in the sense of 'relevancy' or anything else?
Natural as in:
Posted by somebody that has no personal gain by creating the link, but because he/she thought it would benefit people to visit that page.
That means almost automatically that there is a relevance, but not always and not always an obvious relevance. One example of a relevant "natural" link that would be very hard for an algorithm to detect in terms of relevance, is the link I put up on an engineers' forum for David Amerland's book "Seo help". SEO in itself has nothing to do with engineering, but the majority of the members of that forum are small business owners and a quite a few have their own website.
Some of those guys have done a mutual link exchange; the relevance there is nigh on 100%, but it is still not natural because the majority of those putting up other people's links have virtually no chance of that link being of any use to a visitor. The latter are therefore effectively (almost) blackhat and definitely for serp manipulation purposes.