Some how I feel pvp tends to contradict the general philosophy of divinity games. That doesn't mean it isn't possible (or won't be endorsed by Larian's team) but it just doesn't feel right given the structure and nature of previous divinity games.
Dragon Commander won't be like the previous Divinity games but it is still in the same univere. I don't see why there coulnd't be a PvP mode just for fun.
I suggested that some time ago btw:
http://www.larian.com/forums/ubbthreads.php?ubb=showflat&Number=463651#Post463651
