grimmer - 7:29 pm on Jun 2, 2011 (gmt 0)
My guiding rule is to redirect as little as possible. I've seen many sites that have generated their own ranking troubles over time by being very casual with the 301 status.
tedster, can you elaborate this a little bit more? What kind of troubles have you seen?
We also have over 100,000 possibly duplicate pages, we have tagged those as "NOINDEX" since Panda. We do have traffic and possibly link juice from those pages. After reviewing this thread, we think we shall do "301" redirect on those pages to corresponding pages with similar functions.