The idea behind Dave’s post is to navigate to http://lists.w3.org/Archives/Public/www-validator/ which is a URL string off of w3.org. You post a message and a year later you could have a PR6 backlink pointing to your site.
Lets get down to business. The first thing I noticed about Dave’s post is that the links obtained here have been around for over 2 years. So there has been some serious time to acquire that google trust rank and PageRank. We also know that the URL that is displayed on this site shows the URL as an anchor text.
So right off the bat I can tell you that the SEO value is a lot less than it could be if you could give it an anchor text. The good thing about this site is that it does NOT carry a no-follow tag which “supposedly” is a good thing.
Another reason this link acquisition might be too good to be true is because there are a couple frames within this site and both of them have little or no PR.
In addition I took a look at the backlinks to this site and I noticed something interesting. Only Yahoo has picked up this link, and interestingly enough that is the only backlink that has been picked up at all. My overall opinion of this link find is that it is not all that it’s cracked up to be. If you decide to use it, use it in conjunction with other link development techniques while maintaining a level of ethics when obtaining these.