Late to this owing to a long vacation.
FWIW I've always thought a bit of Pagerank sculpting was a good thing in the right circumstances but, as always, say something as simple as that and it can be vastly misinterpreted. MC's post was a bit of a shocker, especially as it was Google themselves (through some work they did on the Google Video site) that popularised the idea of Pagerank sculpting. Now, the question is would it be a boondoggle to go back and UNDO all the Pagerank sculpting work previously done?
Other techniques that make a difference when done correctly are the flattening of the site architecture (for real, not through nofollow attributes)
What does "for real" mean? Flattening architecture means removing structure from the site - this is not always good or helpful in SEO terms and, rather than flattening architecture, the presence of nofollow usually indicates an attempt to UNFLATTEN architecture. An example of a flattened architecture would be a crawlable CSS menuing system in which every page on the site was linked to by every other page. If this is handled through, say, cascading pull-right menus, then each tier in that menuing system represents a flattened layer of the site architecture. The use of some Pagerank sculpting, whether through nofollow or anything else, can really help to re-establish the flattened architecture. BTW Pagerank sculpting is perhaps too pejorative a term in this case ... it's simply site architecting.
That said, anybody who knows me knows I believe that nofollow should be dropped. It's simply a Pagerank manipulation tool. But since it isn't dropped, and since it's only (Google) purpose is Pagerank manipulation, I don't see anything wrong with people using it for that purpose until it finally goes the way of the meta keywords tag - valid, but deprecated. In fact, meta keywords and nofollow have quite a lot in common: they were both bad ideas in hindsight (and even with foresight!), initially provided with the best of intentions and a little naïveté. But architecting your site for search engines and users is not a bad idea.