Now, I know this server is only PVE (and with good reason). That being said, I've discussed with a few players the possibility of a PVP arena. This would NOT Make the entire server PVP.
The PVP arena would be much like the mob arena, where it is a secluded building and a ready up area with signs for classes. Players could choose between the classes and upon a timer and being flagged as ready, would enter the arena. The arena itself would be much different from the Mob arena, as it will have buildings to hide in, obstacles to take cover behind, and narrow alleys for possible ambushes. (a lot like a paintball arena, only MC).
Depending on the popularity of it, you could also add Team Deathmatch, where factions could PVP.
A few things to note about the arena:
1. Personal items from the PVE world have no effect in PVP, and a death in PVP will not effect PVE worlds.
2. MCMMO ranks could potential make players unbalanced, so this will be included in the poll.
3. One thing to consider is a rewards system. (1st place-Diamond, 2nd Place- Gold, 3rd Place Iron, etc)
Please let me know what you all think, and if you vote yes/no please give an explanation to better refine the idea. Thanks!