Actually, the "griefer" is an extreme situation. Open PvP would probably work as most PvPers would probably prefer the challenge of fighting other PvPers rather than just hunting down the easy kills.
The problem, imho, is in trying to provide the reasonable, well-adjusted, PvPer with a system where his/her gameplay isn't just as destroyed by the griefer in having their mechanics screwed up just to deal with the griefer.
If a player imposed mechanic is in place that runs the griefer off the server... both sides win... someone correct me
Ok, I guess that's $15 less a month but would probably pay for itself pretty quickly.