rango - 12:14 pm on Aug 14, 2012 (gmt 0)
Among other things, we have tried a similar thing to get out of panda. Noindexed several million image pages from our site. Only a select ~30,000 of the featured ones are now allowed to be indexed.
It made no difference wrt panda. Though it does mean less activity from googlebot on those pages which is a good thing for server load. So it was still worthwhile.