The Security Mentor

The Microsoft security bulletin says that it affects just about every version of Windows. This is another bug in which using Internet Explorer to look at the wrong web site will let the bad guys take over your computer. Bad guys are already attacking through this security hole.

IE7 is affected.

Until Microsoft releases a patch, it looks like turning off Active Scripting would protect you at the cost of making a lot of web sites stop working right for you. Really, you should continue runing Firefox as your default web browser until you're running IE 7 on Vista and it's had some time to prove itself.