I like PvP. I find PvE boring, particularly in leveling a second wizard. Why not give me experience for PvP matches so I wouldn't have to PvE? I'm not asking for awesome experience here, just something that would allow me to level while I'm doing something I enjoy.
I can think of several ways people could try to use this to power level. Maybe make the experience based on the number of spells cast where the amount of experience would be less (maybe half) than that for an equivalent amount of time spent questing?