After reading through this Google Webmaster Help thread and seeing the response by the Google Employee Wysz it really made me think about issues I have seen in the past and present on sites that have came to us with issues where they used to rank top 10 for keywords and now they just have slid back and can’t really recover. Before if you were slapped with a penalty it was usually -10, -50 or -1000 and gone completely. Now it seems these penalties are not so obvious anymore. Maybe Google could be throttling back just a specific page from ranking or perhaps an entire site from breaking the top 10 or even the top 20.

Read more and post your thoughts on this below: http://www.google.com/support/forum/p/Webmasters/thread?tid=2903c4863fa12e7c&hl=en