I would suggest looking past the dup content issue and reading up on the other issues with google. Dup content doesn't always mean copied content. There is the problem with being on a microsoft server without asapi rewrite.. myriads of problems..suggest you start here- [webmasterworld.com...]
Duplicate content is weird. I was browsing my competitors and one that ranked #1 for a given widget had 100% word for word content from the manufacturers page - exactly the same amount of content and in exactly the same order on the page. Obviously the manufacturers page was around first and most likely indexed first so duplicate content is still quite a mystery to me at least.
trent, I have noticed in the past few months that G is paying less and less attention to lower PR sites and no attention to lower PR links. When they knocked down PR by 1 across the board about six weeks ago, they slowed down all refreshes and page inclusions for these sites as well. My take from this is that you have to distribute your PR as evenly as you can across any page you don't want in Supplemental. This is strictly my organic view from dancing with G very closely since its birthday. You have to get PR5+ links or your new pages will only get a looksee from G maybe 4 times a year. Google used to be pretty nimble at recognizing new pages and changes, and it still is, but you have to be a big PR player to get that treatment. Google wants you to impress it with great links and it's Talk to the Hand if you don't.