Assuming Hughes continues to overachieve like he did in his last start. When there's no reason to take young Phillip out of the rotation from Wang's spot. There's no easy way to handle it and the only right decision would be to leave Phil Hughes in Wang's spot.
Taking a look at Joba if he keeps up the good work he's been doing. That also presents a problem with the Wang situation. Who goes where? What happens to who? If Joba keeps it up I don't see a reason to take him out either except for maybe the fact that he could just go help out the bullpen as they almost blew his win last night.
Of course this all depends on how Wang's recovery goes. If Wang's recovery goes well and he looks on fire in a spot start or in AAA he could find himself back up the majors but I don't know how this is going to look.
If the recovery doesn't go well then Hughes and Joba will probably remain in the starting rotation.
I do however think that Joba still belongs in the bullpen, having quality relief pitching is much more important than your fifth starter.
If I had it my way then Wang would come back great, Hughes would stay in the rotation and Joba would be in a relief role once again. Let's not forget how dominant Joba can be out of the bullpen and what Wang and Hughes are capable of.