We were under the impression that Microsoft believes that almost all x86 Windows servers will be of the 64-bit variety by 2007, when Longhorn Server is due. So it's a bit puzzling that Microsoft is now acknowledging that it will introduce 32-bit flavors of Longhorn Server, alongside the 64-bit ones. The official word is Microsoft believes there will be a transition period, and some customers may want to run Longhorn on their current machines. But how well will the next version of Windows run on older-model systems? Stay tuned.