Ubuntu has been working with touch for some time now and I would expect it to work adequately. I assume the keyboard/cover emulates a keyboard, so keyboard access should not be a problem. My worst fears come from hardware support. After having bad experiences with laptops that come bundled with Windows, I am fully aware hardware can be designed not to work with Linux.
Because there is no Surface Pro 2 equivalent that will run OSX. And by "run OSX" I mean "made by Apple" because there's no other way to run it.
And I doubt very much that the Pro 2 can do Linux well - can any tablets? I'd be interested to know the state of Linux touch interfaces/drivers.