In regards to roles, I also can't see Leia as a fully fledged Jedi. I think she'll still be in politics. Maybe even the Chancellor. Obviously her Jedi powers will be made apparent, but I don't think she will be a Jedi Knight. As for Solo, as someone said earlier, I can see him as a retired old pirate longing for one last adventure at Chewie's side in the Falcon. He'll almost certainly get his wish in Episode 7. Crap, just thinking of all these possibilities really makes me hope to high heaven that the original characters are in it. I will truly be gutted if they're not. Obviously I will still be excited, but I won't lie, my excitement levels will probably be slashed in half.