This case is now over. The Santy worm is not spreading any more, thanks to Google.
Google started filtering the queries made by the worm around midnight GMT, effectively stopping the spread of the worm. Apparently they are doing this based on a combination of the search terms and the User-Agent header field.
(Above from the F-Secure weblog, removed link due to TOS.)
They also had voiced confusion over the right people to email at Google. Looks like F-Secure is linked up with the Google security folks now which should be an example for other anti-virus companies and other search engines. ;)