Great ideas!!! I'm a PvPer so....
I love the dueling in town concept (reminds me of playing WoW :3).. Hopefully people will 1v1 there and "rushing" is for normal PvP. How about bigger maps, larger scale, or free-for-all (no teams) map? How about siege weapons?
Hmm... How about capturing points and implementing more strategy and teamwork? Just some ideas.