World PvP could totally be. Just take the Wintergrasp incentives, improve upon them, offer expansion-life scaling rewards for persistent encounters outside of the main event, split it up into two zones and simplify it into large combat or basic war games.
This is of course, assuming you mean just general world PvP and not back and forth ganking. I really don't find any MMOs post-'98 UO got the feeling of a dangerous, player run world anywhere near right so I dont partake in that at all.
Not that I expect them to do this, Blizzard loves to overdesign on their attempts at world PvP.
Oh well, rated BGs GO. Excited to try those way more than anything else. Nothing rocks more to me in a modern MMO to me like a super tense WSG premade vs premade. So much fun.