I use it as a DAW controller to record and playback. My sound room is downstairs from my CR and it is great to be able to set up mics when others are recording or stop/start recording when I am the only player. I have a snake that is built in the wall and a duplicate set of monitors in the sound room, BTW. It's a bit unique/odd I suppose, but the iC Pro solves a lot of problems with my setup.
When I am sitting at the desk, I just use my trackball and keyboard, and I think this answers your question? I have seen pics of studios where the iPad is sitting in a holder near the desk so I suppose there is something some producer has figured out to use it for? I am not clear what exactly. The whole touch screen thing is the wave, yes, so it won't be too long before iPad apps will be improved for many things in the studio. I understand that Steinberg is improving/revamping GA so it's possible we may see some iPad app appearing for it. ?? This seems a natural to me but I am just speculating. Will it replace a keyboard for most DAW duties is something that remains to be seen. Either way, keyboards will always be around because people type so I think it is important to master the keyboard commands. Well, just my thoughts and I hope I answered your question.
Edit: I just watched the new Steinberg video and it does seem that there are plenty of keyboard replacement options using an iPad and iC Pro. Hm, maybe I will rethink my process!
Cubase 6.5 (6.5.5) and 5.5 (5.5.3), WaveLab Elements 8, iC Pro remote app, LoopMash HD, Win7 64-bit, Intel C2Q9550@2.83GHz, 8G ram, Radeon HD 6570, Gigabyte X48-DS5 MB, Mackie 1640i (FireWire), M-Audio Keystation 61es controller via an M-Audio Midi-Sport 1X1.