Yesterday Immunity Inc. published a flash movie demonstrating compromise of a WinXPSP2 system using an exploit they've developed for the IGMPv3 vuln that was announced by Microsoft earlier this month.

You can see the video here: http://immunityinc.com/documentation/ms08_001.html

And read a ComputerWorld article about it here: http://www.computerworld.com/action/article.do?command=viewArticleBasic&articleId=9060118