Nofollow is dead
According to Matt Cutts, PageRank sculpting is now dead and has been for some time; people simply didn’t notice the change in Pagerank designation that Google secretly made sometime ago in 2008.
At first, we figured that site owners or people running tests would notice, but they didn’t.
Classic PageRank (ignoring the decay flow factor of 10-15%) was seen like this: a site with “10 PageRank points” and 10 outgoing links (5 of which are nofollow) will give each link without nofollow 2 PageRank points. However, now a site with the same structure will only give each of the links without nofollow 1 PageRank point. Links with the nofollow attribute are designated their respectful PageRank, but when the times comes to assign it, this PageRank simply disappears.
What does this mean for webmasters? Matt Cutts suggests that you let PageRank flow freely throughout your website; I agree with him to an extent, but I think that people will still try to PageRank sculpt in a new way. This new PageRank sculpting will encourage webmasters to reduce the number of links on a webpage or hide these links away from getting PageRank by using iframes or other techniques to ensure that the other links on this webpage get the maximum flow of PageRank. Some webmasters might even consider removing comments on their blogs because all of the links from comments is destroying their PageRank flow throughout their websites.
PageRank is clearly a much more complex topic than this. For instance, link placement on a webpage affects the authority it is rewarded; a navigational sidebar link is going to be designated less PageRank that an in context link. Time will tell if people start this new PageRank sculpting, but I doubt it will be beneficial for the time it takes to implement and its implementation will likely make a website awkward. If it does become a new practice to optimize websites, one thing I believe is that Google will pickup on this and change their algorithms accordingly.
F The Pagerank!!! I would rather have my blog filled with comments than to have PR10.