What returning characters do you think will die in Episode III?
I think all of the Jedi Council will die. We probably won't see them all die, but there will be references to their deaths throughout the movie. We will deffo see Mace die.
I think Nute Gunray will die. He was supposed to go in Episode II by Jango's flame thrower, but the scene was dropped . Lucas must have plans for him in Episode III then, and I think he will die.
Mas Amedda. No reason for thinking this, appart from the fact that he isn't with Palpatine in ROTJ. He will probably be killed by the Jedi when they're trying to stop Palpy.
I'm not sure if Padmé will die or not. I would like to see Anakin kill her and Leia's memory of her could be put down to her use of the Force, or something along them lines.
Cleigg Lars - he's not in Episode IV (but could have die between 3 and 4).
I also think Jar Jar will die, but I hope he doesn't! I want him to be added to the Imperial Meeting Room on the Death Star in ANH Archival Edition.