I know you already know about this, but this is for my reference, so I remember to look here in the morning.
Find here Microsoft IT’s early adopter experiences, best experiences, and lessons learned from our own deployments of Messaging solutions within our global enterprise. By leveraging our best practices, you can make decisions about how best to plan for, deploy, and manage Microsoft solutions in your own environment.
I am interested in these, but check the rest of the list out:
TechNet Webcast: How Microsoft IT Does Storage Design In Exchange Scale Up Deployments (Level 200)
This is actually a really good webcast!