This reminds me a lot of the Palm Foleo, a device I worked on ten years ago. It was mini-laptop sized, designed to be a phone companion, but it worked over Bluetooth and actually ran its own applications, just using the BT connection for continual data sync. This one has a much better chance of actually shipping, and the advance of computing power has made it a lot more viable. Good luck.
By the way, did the GPL code used on that ever get released, assuming the demo units counted as distribution?