It may run on Itanium, but it doesn't support more than a fraction of the x86 server functionality.
http://technet.microsoft.com/en-us/library/cc772344(WS.10).a...
I don't see how Microsoft will ever shed the x86 legacy in Windows. Intel would have an interest in killing off arm-based laptops with aggressive pricing, and there really isn't any history of Windows developers rebuilding apps to support other chip architectures.