Blizzard has posted a helpful page of tips on how to run, in my opinion, the best setup of organized World PvP so far: Halaa, the conquerable city in Nagrand.
The tips are pretty straightforward: stick together (team-- where's my CS homies at?), do as much bombing as you can before heading into the town, and make sure, once you've liberated Halaa from its evil oppressors, that you stick around to keep control and defend against any counterattacks. One thing I like about Halaa is that the Wyverns make it super easy for even lower geared players to join the fight and make a real difference. Plus, the layout is done well, and I like, as we heard at BlizzCon, that Blizzard went with a pretty persistent reward-- it's no fun to conquer something just to lose it again in 5 minutes.
And Halaa, surely, will serve as a model for the next big noninstanced PvP zone coming in Wrath of the Lich King, Lake Wintergrasp. Blizzard hasn't actually designed the zone yet, but they did share their goals with us-- multiple targets and rewards, a persistent effect, and of course while Halaa doesn't have them, siege weapons will make an appearance as well.
So if you haven't tried Halaa yet, definitely check it out. From everything we've heard, this kind of thing is the future of where World PvP is headed.