First of all, this needs to be a distributed application supporting the sharing of ink, with real time drawing on multiple tablets. The best way to handle real time broadcast of ink, is to send groups of ink packets,and then reassemble them using the real time stylus. This will require developing some of your own rendering routines. A client server architecture is probably easiest, and you are welcome to build on someone elses networking package.
One aspect of this project to explore is to have the model of infinite sheets of paper, so that writing can be done any direction. This opens up many interesting navigation problems - how do you keep track of your writing, and conveniently move around.
This project should consider an application scenario, to allow possible testing and evaluation, and to motivate design choices. One natural scenario is to target student study sessions - the type of sessions that take place on the whiteboard walls in the break out areas in the Allen center - can shared note paper on Tablet PCs be used for the same type of collaborative work (with the advantage that all participants come away with a digital record of the session).