Why not? Right now, I basically always have my iPhone with me. Often, I also have an 11" Air with me. But there's a lot of redundancy between the two, I have to keep them in sync, and tether the phone to the Air when off WiFi. This sounds like a credible solution to eliminate that redundancy and it wouldn't mean carrying an extra device.
Honestly, I'd probably fund this project right now if they had a tablet or notebook docking accessory in the plan.
