SVG is not part of the plan for IE7. This is definitely something we are looking at for a future release though.

The IE team blog at http://blogs.msdn.com/ie is doing a pretty good job of explaining the feature set of IE7 with additional documentation at http://msdn.microsoft.com/ie

If you want to hear more about the future of IE then you should come to Mix06 www.mix06.com where Dean Hachamovitch the General Manager of IE will be giving a talk called "The Future of IE". There will also be IE team members including myself at the conference. I'll be helping in the IE7 Compatibility lab where we will be helping people prepare websites for IE7 and collecting feedback.

Thanks
-Dave