Source -When the system requirements for Microsoft Office 2010 were first posted, we noticed that Windows XP 64-bit was mysteriously absent. We contacted Microsoft, and the company explained that while deciding on which versions of Windows to support in the next release of Office, it weighed the user experience behind the versions against broadly dropping support.
Why Office 2010 won't support Windows XP 64-bit
I guess they don't want two BETAS running, however when they finally release it to manufacturing you can rest assured the slice of the market which belongs to 64bit users will be even greater than it's already become.
Loads of programs which are designed for x86 platforms work beautifully on x64 rigs, so I doubt it'll worry end users much - nor Microsoft, who have very little serious competition to their Office product :)
That statement kinda gets to the point I will expand on.Frankly, we believe Microsoft would kill off Windows XP 32-bit support for Office 2010
I think more accurate is that,,, XP 32bit is more entrenched in society than 64bit and as XP Main Stream Support has already ended, they did not want to have to support a lower market share version, would cost more than it's worth.
This is also why I hope that Windows 8 is 64bit only, no more 32bit and force the issue.
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