Bob Muglia, senior vice president of Microsoft Server and Tools, announced this at the IT Forum being held in Barcelona, Spain. He also said that while the first release of the upcoming next-version Windows Server family of products, code-named Longhorn, will be both 32-bit and 64-bit, the future update release to that, known as Windows Server "Longhorn" R2, will bring the complete transition to 64-bit-only hardware, while still benefiting from 32-bit and 64-bit application compatibility."
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This should also kill any speculation or question whether there will be 32-bit Windows Blackcomb Server. I predict the same on the client side, since Blackcomb won’t be ready until 2010/2011. Longhorn Server R2 should be coming out in 2009.