Are there any well known Problems after migrating the forestFunctionality + domainFunctionality up to 2008R2?
The Biztalkserver runs under 2003 SP2. It will be replaced in the next time so I won't migrate the Biztalk to the aktual Version.
Only for for the Biztalk: we use one Exchange 2003 SP2, our main mailsystem runs under 2010.
I don't found a compability matrix, only for the 2010 Biztalk.....