As many of you already know, Windows 8 has a just released a Developer preview that it seems like can be put on any compatible system. However the ARM processor based tablets are not compatible.... With THIS release. Supposedly there is going to be a new release in the near future that will support ARM processors. However, some of the tablets that are out will support windows 8, and here they are:
Asus Eee Slate
HP Slate 500
Viewsonic ViewPad 10
Arcos 9

If i have forgotten any, feel free to Shout them out.