I had wondered about that since May and got a partial answer to this with some of the DC’s today. My site, which had never disappeared from Google, did. In its place were dozens of sites that had duplicated my content. This was very interesting in that I’m an expert in finding duplicate content but this junk surfaced out of the "middle of nowhere". It doesn’t appear in MSN or Yahoo and never did. Even more interesting is these sites utilized every conceivable dirty trick you can think of. A quick view revealed at least ten running site maps of my site and replacing my url’s with theirs. Also cloakers of every type, scuzz sites, previously unseen scrappers, and forums that posted entire stolen pages were to numerous to count.
Bottom line is Universal search is crawling the underbelly of the Internet and letting every huckster and schemer around into the results. Duplicate content, which might not have affected your site previously, may well do so in the future. Google’s better idea (ROFL) may soon increase a webmaster’s work even more in combating duplicate content.