Fewer links should have nofollow added to them. Any user with karma more than ~100 should get the benefit of the google-juice in their profile and even in any links they add. There is also benefit for the owners of those linked sites and to web denizens in general---the fact that a LW-er with karma > 100 linked to them is important information.

But beyond that, even the internal links on the front page are nofollow! Certainly links to lesswrong.com and the LW Wiki should not have this tag.