The new Surface tablets look very interesting. I can think of several things it would be good for. But Pro Audio is not one of them. You have to use the right tool for the job.
I have a desktop computer (6 core CPU, 16GB RAM, 27 inch monitor) for my audio work. Why would I want to use a tablet? That just silly.
Just because you can, doesn't mean you should.
Well, either device could still be useful for lightweight or mobile recording, say a band practice or even hooked up to the mixer at a live show (assuming the storage is adequate). But it would definitely need apps designed for the form factor to be anything more than "because you can".