ichthyous - 3:11 am on Aug 7, 2008 (gmt 0)

Yes, your approach may be clarifying for Google which URLs really "matter" and that clarification can help. But a lot of the outcome will depend on an extremely thorough attention to detail.

Well, as long as the urls won't be pulled from the index for 180 days simply from blocking them in robots.txt I will leave it in place and work on zapping the remaining dupe content and see if that has any effect on traffic. I made a change to robots.txt to allow other robots to index those pages but not googlebot. I suspect that if google categorizes those urls as dupes they aren't performing well anyway, and the traffic I have lost from those dupe urls was coming in from from yahoo and other sources. If there's no improvement in traffic over time I may remove the blocked urls from robots.txt and just redirect them to the proper url....what a job that will be!