Just got an email about a new trojan exploit- Exploit-WMF, affecting the Windows Picture and Fax Viewer on Windows ME, Windows 2000, Windows XP and Windows 2003, exploiting the Windows Metafile vulnerability.
Apparently; the google desktop thingy will index it and it executes:
http://www.microsoft.com/technet/security/advisory/912840.mspx
http://secunia.com/advisories/18255/
http://www.f-secure.com/weblog/archives/archive-122005.html#00000754
http://www.grc.com/sn/notes-020.htm