I voted turned based like ToEE. That game had serious flaws, but it still shined because it used the game rules as written. If they did a really polished line of games like that one with the 4e rules and put it out on all of the major consoles as well as PC... I have to assume it would do well.
I'd love an MMO, but we have one and I hate it. Maybe I'm a sheep for loving WoW, but that game works for me. Also; as cool as Eberon is, I don't think they used enough of that setting to really showcase it. I'd have rather it been set in greyhawk and feature the various modules of old as major instances and quest lines.