"We will support 32-bit and 64-bit," Bob Kelly, a general manager in Microsoft's Windows server group, said in an interview yesterday. "We're in a transition period from 32-bit to 64-bit. We believe that will take a while."
Microsoft will ship a 32-bit version of the Longhorn server so customers can run the new operating system on existing server hardware. At the time the Longhorn server version ships, Microsoft expects that the vast majority of new x86-based servers, if not all, will be shipped with x64 processors.