Microsoft has stated that the still in development Windows Server 8 will support only 64-bit processors, minus the Intel Itanium. This is good news for most, as most (if not all) server grade processors are already 64-bit and have been for quite some time. Some of us still have older servers for development and testing and will be forced to upgrade, which is a shame (ok, it’s a great excuse to upgrade my home server!).
With the advent of Windows Server 2008 R2, Microsoft dropped support for 32-bit (x86) CPUs. In fact, at this point in time, the best choice for customers running servers with x86 processors, as far as Windows Server is concerned, is to run the plain vanilla version of Windows Server 2008. Reger argued that it was only natural for Windows Server vNext to move on from Itanium, just as Windows Server 2008 R2 moved on from 32-bit processors.