There are some new exciting videos at the Microsoft Exchange Team Blog, aka, You Had Me At EHLO. You can watch a TechEd talk with Terry Myerson, General Manager of Exchange, or if you prefer to see demos about Exchange 2007, there are also lots of them available.
Here are the links:
Technorati : exchange 2007, teched, video
Del.icio.us : exchange 2007, teched, video