We're all excited about the upcoming version, anxious to get some information. Luckily for me, I live in a very technically oriented country, Israel, the country that brought you the latest Pentium technologies and ISA server.
TechEd event in Israel is one of the best sources for information about Microsoft technologies, if you know your Hebrew. Luckily for most of you, the powerpoint presentations are in English and are downloadable.
Exchange 12 Technical Overview Part I
Exchange 12: Look Ma' It's Alive! - Demonstrating Client Access and Unified Messaging
Exchange 12 Technical Overview - Part 2