Imagine a World of Warcraft (or any other MMO of your choice) PvE server ruleset where:
*NPCs cannot be killed by the opposing faction.
*Wintergrasp/Tol Barad/world PvP objectives do not exist.
*You cannot flag for PvP at all in the open world.
*PvP only happens in consensual duels, cross-server battlegrounds, and arenas.
How would this affect you? Would it be an improvement, since you would never have to worry about your questing experience being hindered in any way? Or would it be boring and static, with no possibilities of on-server faction vs. faction combat?
If you’re normally a PvE player, would you consider playing on such a server?
Battle Priestess 
I don’t PvP often, if at all, so keeping it the same or changing anything doesn’t affect me. However, I’m all about choices, so the removal of any established system in an existing game is a no-no as far as I’m concerned.
Oh I agree, I don’t think any game should change mid-stream with existing servers. I’m thinking more along the lines of new games, or old games releasing new servers with that particular ruleset. 🙂