Not any more - but originally they were, hence some confulsion. The new rel="nofollow" attribute was created for one purpose and quickly used for others - even with explicit "blessing" from Googlers. I was one of the hold-outs, exactly because of that original purpose. However, in a few case now I've given it a try since it seems to be blessed by Mountain View.
Maybe for some sites. I've only seen some little nudges so far, although I did advise one site to add the rel="nofollow" in a case where every page had a major block of 15 "customer service" links. In a case like that, it could make a "huge" difference.
[edited by: tedster at 9:47 am (utc) on Dec. 10, 2008]