I was going to post something about Windows 8 tablets and good audio latency and maybe class compliant MIDI controllers but Peter Kirn already said everything I was wondering about here (and he's much better a writing than me)
http://createdigitalmusic.com/2012/06/microsoft-unveils-two-surface-tablets-but-questions-abound-will-they-hold-a-tune/

I don't have much hope that ARM based tablets will be useful for music apps but there's no reason why the Intel based ones running full Windows 8 CAN'T work just fine for pro audio apps with very little latency PLUS since they're basically just keyboardless ultrabooks they should work with external USB audio interfaces and their ASIO drivers.
If more software was written to take advantage of WASAPI we wouldn't even need to bother with ASIO anymore.
I certainly hope they have no annoying DPC latency too.