Miami doesn't have to get that much better. In their first year, they were in the Finals.
The Celtics face a uphill battle against them at this point. A battle I think they can win if they are healthy and if they strengthen their C spot.
For this year, the only Rondo move I would make is to trade for Paul or Williams. That's it.
Unless there is multiple injuries to the three stars. Then, it might be time to think about planning for the future. (big time season ending injuries)
Rondo is a big part of this teams future. I am just not sure if it is as a player or a big trade piece.