In order for Lucas to pull off an effective dark movie, he's going to tie up all the loose ends. We will see the demise of Amidala, Mace, and most of the jedi. If they don't show us this, I guarantee you they will make three more movies.
Episode III (what I think will happen)
1) There will be a huge space battle, where we will see Anakin doing some amazing moves. (Obi-wan: He was the best starpilot in the galaxy).
2) Mace will kill Dooku. His claim to fame can't be killing Jango, that would be stupid.
3) The entire movie, Anakin will have the sabre that Luke gets in IV.
4) Mace will be killed by Anakin, then Obi-wan will use Mace's purple sabre in his fight with Anakin.
5) The Jedi will be wiped out. Even Yoda and Obi-wan are believed to be dead by the end.
6) The twins will be born. I think the end of the film will jump ahead in years. So we won't see all the Jedi killed, but we will see that the twins are a little older, and that bad things have happened.
7) I still think Anakin/Vader may kill Amidala when she won't reveal where she's hidden the kids.
she will fall in love with Bail Organa and go to Alderaan with him, this is why he 'adopts' Leia.nah I got the impression that Bail have a wife, at least when Lukes ask Leia about her memories of her REAL mother. To me this sounds like she had an adoptive mother as well.