As title! MS has released the official WMF exploit patch several days early onto Windows Update. My 2 computers run 24/7 and both had updated and re-booted (by themselves) sometime through the night.
If you run Windows XP and do not have Windows Update doing these things automatically (which you should) then I'd recommend going and downloading the patch now. It's only 250k, and it's very important for stopping the critical vunerability which allows code to be exploited from an image file.
Download at http://www.microsoft.com/technet/security/bulletin/ms06-001.mspx
Once again, I would seriously recommend all XP users to install this ASAP.
Malky