Was just doing a bit of catchup and caught this post.. Looks like Nathan has announced the release of an/the Exchange router for Exchange 2007.
"Hi All,
For anyone trying to integrate CRM v3 with Exchange 2007 another piece of the puzzle has just been released!
Check out and download the Microsoft Dynamics CRM 3.0-Exchange E-mail Router Update here
http://www.microsoft.com/downloads/details.aspx?FamilyID=f7656f0f-4195-4a7d-b654-2786787e1422&DisplayLang=en
Cheers
Nathan "