Interesting discussion. I would only like to state my opinion on the issue on employing a nofollow attribute to an outgoing link - this I think should be done when you don't want to vouch for a site (therefore passing
PR). In the eyes of the search engine, a link is considered as a vote. For me, its only a fair practice to allow the leak of
PR if such site is deserving enough - this should also be based on individual Webamasters.