maximillianos - 3:09 am on Apr 7, 2011 (gmt 0)
dickbaker- If I may offer my perspective. I would not noindex pages solely on their current rank. I think this algorithm may do a site wide penalty, in which case you can't be sure why certain pages rank really low. Maybe it has nothing to do with quality, maybe it is the back link profile, maybe it is on page seo problems that can be fixed.
I would caution over doing the noindex thing. Just stand back and decide does this page offer decent value? If the answer is yes, who cares where it ranks right now, leave it in the index.
Something that gets lost in this mess is the fact that there are about 30% of traffic (or more in some cases) that is coming from non-G search engines. Noindexing will affect you on all the search engines.
My stance has been to just eliminate/noindex the stuff you would not want to encounter in the search results yourself.