Well, the commute is about 6.5 miles each way through the middle of phoenix which is pretty much all paved roads and flat. I really think that timbuk2 bag that converts from messenger to pannier would be the ideal grad school commuter bag. It has a slot for up to a 15" laptop and reviewers were saying that everything else they wanted to lug would fit fine, and it is thoroughly water proof in case I get caught in a surprise storm.

As for the bike itself, I had thought about a one speed but, I think I would like to have a range of gears in case I ever decide to to some trail riding in the area. Also, the idea of the internal hub with the belt drive sounds like a bullet proof solution against dust and road grime.