If the game focuses primarily (and only) on PvP as an endgame, I don't think it will be all that successful or long-lasting. Rather, I would love to see them focus on a cooperative-only mode where you can team up and conquer a map full of NPC's, some of which should be very tough. This would require them to have persistent maps, and the ability to enter an either "invite only" world, or an "open" world, and proceed to work with your allies to defeat the NPC's and dominate the map. Diffiiculty levels can be ramped up and down depending on the performance of the player alliance to keep things interesting, and rewards can be given like unit unlocks or custom looks.
I'm hoping the game is not entirely made up of skirmish PvP battles and kingdom building.