I really want to see a game that gets rid of the holy-trinity setup. Make every class a dps type class. Then give each class the ability to keep itself alive during a fight somehow (healing, repairing, some sort of defensive shield, etc.) Make aggro more random and mob damage more aoe.

Actually, a hybrid FPS / MMO would be awesome. Start with FPS mechanics and gameplay then start throwing in MMO aspects; grouping, quests, character development; etc. THAT would be fun to play.