Agreed. There's a lot to read, but that's good if you've never played Diplomacy. However, I would suspect most people interested in this *have* played it. The interface seems very nice so far (I've only been through about 20% of the tutorial, and that took almost 15-20 minutes. The playing surface looks nice, very boardgame like, with some nice touches like a generic ripple effect for water and the units have shadows that ever so slightly move from side to side to keep the board from looking too static) I wonder though about the AI, since apparently there's no way to actually play against it in the demo.
Proabably a moot point as Diplomacy really needs to be played with humans (it has multiplayer), as the negotiation is just as important (if not moreso) than the tactics.