Raith5
Adventurer
YOU, my friend, are an optimist!
To have a game with deep, tactical combat like 4e, you need to build the classes for it from the ground up. Even a very robust set of alternate rules is not going to get you there. And I don't think we're going to see a set of robust alternate rules. I think we're going to get three pages and a sidebar in the DMG.
But maybe I'm just a pessimist.
I think the worrying thing is that there has been little attempt to engage with their former 4e customers and say "hey, we are thinking of you" and there will be some 4e options present. I mean there are clearly some 4e elements like at will cantrips present (even though these are also in pathfinder I think) but i would think they would try to do more to keep their most recent customers in the tent.