[mcpherrinm]

You probably can't use any proprietary OS on it: Apple certainly would never license iOS, and I doubt W8 would either.

Android, Ubuntu Mobile, Firefox OS, Meego, Tizen are more likely candidates.

[ForHackernews]

Windows 8 runs on commodity x86 hardware. Assuming there's driver support, it should work.

[TazeTSchnitzel]

Phones aren't commodity x86 hardware in the way PCs are. The hardware can't be enumerated.

[leoc]

Can you buy a licence to run it legally though?

[poloniculmov]

Windows 8? Yeah. You can't buy Windows Phone 8.