I always thought Greivous = Maul would be neat, but it simply is not happening. The happy and triumphant Senator Palpatine wouldn't be like, errrr......can someone go get that dead sith's body? I uhm, want to make sure he is indeed dead. No. The Jedi can't have it after I see it.
Not to mention all of the information we have been fed about the pre-cyborg GG.
Carnage
My prediction:
Music will play at some point during the movie, and there will DEFINITELY be an explosion, and maybe even a droid.
I predict the ships will be made of some sort of metal, and most, if not all windows will be see-through. I bet Yoda will be in it at some point, and there will definitely be some sky.
I won't go all out as to say there will be any lightsaber fights in this one. There has to be a limit to the expectations. Sometimes you've gotta say to yourself "Hey! Woah dude! Slow down!".