Scott Guthrie is on fire! Recently, he's posted updates on the development of ASP.Net 2.0. His first post is an enlightening look on the Microsoft development process. His second post goes in to to the intricacies of the testing process. Here's the amazing part, they track and test 105,000 test cases and 505,000 test scenarios. Simply amazing.
UPDATE: He's clarified how his team tracks bugs.