The page where I first saw this is here....due to this vulnerability, the simple act of visiting a website could infect computers, if it contains a malicious WMF, opening the door to Trojans, worms and all types of threats. This vulnerability lies in the way Windows handles WMF (Windows Meta File), so all programs that can process this type of file are affected. These include Internet Explorer, Outlook and Windows Picture and Fax viewer.
Microsoft says to wait until they put up their fix in another 5 days... I say screw them and fix your shiz!
I downloaded the hexblog exe and haven't had any problems and I don't think anyone else has either. Links to the fix and other info can be found on the above page.