i just checked my webmaster tools account and i have the same result. but in my case i have many nofollow links from yahoo answers and they havent indexed. i dont know why
Even if the pagerank of our site does not increase due to nofollow backlinks, still google might give some importance to such links specially if they are from big sites and we have a lot of such links. This is definitely good news and I will try to get many links to my sites, even if they are nofollow.
Yes I have seen this also for long time, and I guess they help for site SERP. Only PR will not pass I guess
I think nofollow are just as important as dofollow. Google, Yahoo and other engines recognise the links and use them for SE ranking equations but probably don't count towards PR. However I think if you have only dofollow links Google could in fact penalise you as it appears unnatural to have only dofollow and very little nofollow just as it does to have only high PR links. Therefore I believe in building a variety of links including nofollow and low PR. It may not help your PR but in the end who cares if it boosts your SE rankings and gets you more traffic, isn't that what it's all about?
The most important thing about nofollow links is the fact that they allow targeting humans rather than search engines, which is a way to boost traffic.
If a link was not relevant, them webmaster simply don't put it in his website. The only irrelevant links are, many times, the ones that are used for SEO purpouses or the ones that webmatsers sells. But nofollow can't be SEO, then its relevant most probably. If Google is smart enough, they will start counting nofollows more than dofollows.