I have to share this one with you - in around three weeks time, there's a series of webcasts on Exchange 12 running over 4 days. The better news is (I'm guessing for US attendees only though) is that if you attend all four webcasts (can be viewed on demand, not necessarily live) and you submit your evaluations before 31st March, there's a small gift of a Microsoft travel mug, plus a chance to win a TechNet Plus subscription. TechNet Plus will get the Exchange 12 CTP (Community Technology Build) hopefully next month.
Tuesday 14th March: Overview of Exchange 12
Wednesday 15th March: Giving the Administrator More Control in Exchange 12
Thursday 16th March: Client Access and Web Services in Exchange 12
Friday 17th March: Message Security and Active Protection in Exchange 12
Here's the registration link