Windows Server 2008 R2 is the last Microsoft Server OS to support Intels older 64-bit CPU, Itanium. While it had a good run, better and lower cost processors (Xeon, Opteron) won out in the end. Some see this as Microsoft moving on towards the future (which is a good thing), while the nay-sayers will claim that Microsoft doesn’t support older hardware. I guess you can’t please everyone, right?
Current support for Itanium remains unchanged.