Rob, one of the Five Testers from VC, has posted a blog entry which looks to become a multi-part piece on on testing the IDE in Visual C++. I think this blog provides some very interesting insights into how testers think about things.
VC IDE testing (issues and processes)
[rob] Since Ron has been entering thoughts and comments on compiler testing, I’d like to add a perspective on IDE testing from VC. I’ll leave it in notation format to encourage discussion of points for which readers would like more clarification.