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It should be possible with Vista (which is EFI-aware out of the box), but you'll run into some difficulties down the road if Apple ever issues a firmware update for your computer...

Actually, Vista wasn't EFI ready until SP1 came out, so you'd need to find a Vista+SP1 installation disk. I haven't tried it, but it should work... You'd still want the Bootcamp disk for drivers.
 
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