Came from another MMO where PVP was highly developed (or rather they kept trying), no doubt to "cash in" on the "I wanna fightcha" mentality. In my opinion it was a major distraction to the adventuring part of the game.
Unless some unique system of PVP is implemented in some seemless way with current adventuring, I think it would be dangerous and destructive to focus too much on it. I'm not a big "Im gonna fightcha" fan so for my 2 Cents it can be an entirely separate game and it would be fine with me.
There's enough Fight games out there to make the kids and macho happy.
The PVE spirit of DND (the adventuring) was what attracted me in years past, and to DDO now.
Now if only I could get experience for each encounter or at least the quest XP penalty could be cut back for those of us required by life to solo, my life would be complete.