The synchronisation between the databases and datacenters from Google takes a lot of cpu time. I think if they play a new algo and made some big database changes on field level or changes on Index-Fields, it could take month to work the changes together. So they made a lot of mini Google dances, mixed with "little freshbots dances". Sometimes it looks in some search results like a broken database. I think that is in this Parts of Google were the biggest changes take part. So a lot of spammers reached the top 10, but only for a short time. If the database changes get together, the search results will be better than ever...
Don't fight it, play it :-)
