Interestingly - Ive noticed one change that has me kinda baffled - they seem to be filtering(censoring) a few more word combinations than they used to - in the past if the phrase had two meanings they would just allow the best site to rank whether it was adult or not. It looks like either their filters are all out of whack, or they are adding some phrases to that list - maybe they are getting ready for the firestorm ahead
The database rollback is definitely there - although like you mentioned Capt - that wouldnt affect a site that had ranked for that long - the only other info I have available right now is that Adsense also went down last night as part of the outage - not sure if Google has any ties between the index and that - but I wouldnt be surprised no matter how much they decline to answer that one