Last November (I know, I'm a little bit late...) Microsoft released the November version of the Microsoft Exchange 2010 Visio Stencils, that include:
- Exchange 2010 server roles;
- Features new to Exchange 2010 SP1;
- Networking, telephony, and Unified Messaging objects;
- Active Directory and directory service objects;
- Client computers and devices;
- Other Exchange organization elements.
It works with the Microsoft Office Visio 2003 or later and you can get it here.