It looks like a great release, I haven't had a chance to use it yet. I think putting Dean Hamatchovich on IE was a great move, I am a big fan of his work.

Three things:

a) Can you do a separate self-contained package of IE9 on MSDN? ie. the entire app in a single folder, so that we don't have to update the core OS. This will help those who want to run older IE's concurrently.

b) XP support. I know Microsoft want users to shift to Win7, but there are a lot of XP desktops still out there (I run it in a vmachine). Is there a technical reason why it doesn't run on XP? We have all of .NET on XP - so is this a political decision rather than a technical one?

c) Chrome style extensions with HTML + JS etc. These are so easy to develop, and compatibility with the Chrome manifest files for extensions would be a big win for developers, users and the ecosystem.