
I don't have a beef with Plagueis. I like the idea just fine in the PT, where it should stay. Gave Palpatine a nice backstory where he murdered his own mentor. Also, its possible Palps was lying about the entire 'cheat death' thing just to get his hooks into Anakin. He lied to everyone else -- why is the Plagueis thing believe to be true? Because you want it to.
Anyway, dead or alive, I prefer Plagueis be part of the past.... and not be some live-forever villain. How will we ever believe he is killed off in this trilogy if he can "cheat death". I can hear the fan-boys now:
he's not dead. He'll be back. He can't die. He's all powerful. -- it's like Devil worship. Very bad.