ETC...
there's a HUGE market for this and there's plenty of games out that cater to every other gaming demographic
OMG yes pleeeeeeaase! I love open pvp but also include consequences that would deter every player from killing each other. Active guards patrolling in and out of towns, fines, jail, or even the inability to gain certain things in the game if you kill someone, like high leveled restoration school spells.
Yes I have played mmos like this. No there is not a huge market for it AND there are two mmo running right now with that kind of ruleset and they only have a couple thousand players. Not a couple million.