It is USB, yes.
I'm in two minds. In principle yes, I would like them to support legacy devices so I could go out and purchase a Fanatec setup, but then part of me wants them to move forward and not hold back.
There's a good reason that they can't just release drivers, and it's to do with the signals that the Xbone uses to control the feedback to different motors within the controllers (pads, wheels, whatever). Don't ask me the ins and outs, I'm no software engineer, but you would think that there simply has to be a very real technological reason why it's not just a case of drivers.