tedster - 10:05 pm on Jul 3, 2010 (gmt 0)
you could ruin the PR distribution of any blog or forum site you wanted simply by adding the site's main page link (or their entire navigation) to the blog comments on any page
That certainly is an edge case, steveb. If Google is doing this for nofollowed blog comments, it would disrupt internal circulation from that one page. But to do any significant degree of damage you'd need to add such a link to the comments on many, many pages, right?
The tests that Bruce Clay and others were doing involved multiple links in the content area. Google does segment the page in their algorithm, so I assume that blog comment areas are treated differently, no matter what.