I personally have play all MMO's (even the bad ones like warhammer) since Ever Quest. They all have similarities as there is no way to make it entirely new but they all have their own differences. If a company can find something really different and not just "we have made blah game, it is the same as wow with new toon skins and better graphics" then they may make something that will dominate wow. untill then imo they will just be imitations of a system that works well