Well, for those that didn't know, IE 7 has went RTM. You can get it at http://microsoft.com/ie . After you install it, look for the patch that isn't out yet, since Secunia says they have a working sample of the first exploit. Check and see if you are vulnerable, I *can* say IE 7 on Vista is not, I don't have IE 7 RTM on an XP machine yet.
Update: Interestingly, I thought that this did not affect Windows 2003 server running IE 7, but I noticed the version I had on that machine was Beta 2. I upgraded to the RTM version and was suddenly vulnerable.
So...this is something that was introduced between beta 2 and RTM.