This isn't exactly breaking news, but there's a very nasty bug in Windows 2000, XP and 2003 that has just recently been revealed being called the "WMF vulnerability." The bug has to do with a vulnerable function in GDI32.DLL library that can allow a malicious hacker/web site to install a virus/spyware on your computer.
What makes this bug extremely dangerous is any program that views images (such as Internet Explorer, Firefox, etc) is vulnerable.
Microsoft is claiming that there will not be an "official" patch for this bug until next week. However, this thing is nasty enough that everyone running Windows 2000, XP or 2003 should take some kind of action now.