walkman - 4:45 pm on Feb 25, 2011 (gmt 0)
For everyone with a legit white hat site with legit unique content I strongly believe that if you login to your webmasters console and do a reconsideration request, explaining the problem, your rankings will return in short order.
If you are serious about the quality of your site and in-bound links, this should be a pro-active step you take immediately.
gford, the problem is that very few sites in competitive fields are clean as a whistle. You can be much cleaner than your competitor, but is it clean enough for Google? It's not an easy decision :)