Okay, with the trade the roster now looks a little like this:
Lineup
1B - Berkman
2B - Biggio
SS - Everett
3B - Ensberg
Lf - Lee
CF - Burke
RF - Scott
C - Aumsus
Bench
Lamb
Lane
Bruntlett
Gimenez or Quinterro
and Palmeiro
Starting Rotation:
Oswalt
Jennings
Williams
Rodriguez
Nieve (these last 2 are open spots but using the candidates Purpura listed as the first 2)
Bullpen:
Lidge
Wheeler
Qualls
Miller
Sampson
Borkowski?
Asencio?
I could be wrong but that roster looks complete unless they deal someone else from that list. The only question mark, or one where a candidate hasn't been mentioned (4th/5th starter), is backup catcher. The other change depends on what Clemens does, obviously, but I don't think that's a question of sending down the least effective starter to make room.
Where else can/should they upgrade?