"_____X_____ should port _____Y_____ to the Touchpad" posts are getting real old when there's no chance in hell it'd happen.
Any 'ports' of any OS to the Touchpad or any other webOS hardware are going to come from the hobbyist community, and no closed-source OS (Windows 8, iOS, etc) will never touch the hardware. Find open-source operating systems to port over, as that will be much more realistic.
From everything they've said, Microsoft doesn't see it as an ARM version and a x86 version, it's just Windows. I doubt they care if one does better than the other, they're just giving manufacturers the option (I say manufacturers because I doubt the ARM version will be installable by end-users... since for ARM everything is just too tightly integrated to the hardware).
True, but seeing how popular the touchpad has become, I wouldn't put it past the hobbyist to get it running on the touchpad once released. If you look at some of the projects going on over at XDA, not hard to believe what a dev community can accomplish in spare time on unsupported hardware. Especially when the OS is ARM compatible from the get-go. Didn't some of the tablets they previewed have similar Qualcomm chipsets as well?