I think Lucas is gonna take us where we only heard little about and definately new places, faces and ideas. *ahem* To go where no SW Junky has gone before ;D lol Sorry, couldn't help it!
There wasn't much about the SW underworld, what life was like for the every day person. I think he's gonna attempt to give light to those kinds of things. No doubt we'll see Stormtroopers, etc, and maybe, though not likely, an new Jedi or two... I always wanted to see what Coruscant looked like beneath the cloud layer and not just in descriptibe words. We might get to see something about Black Sun - maybe even Prince Xizor? How knows? *shrugs* Also, there's places like Nar Shadda, Kuat, Mon Calamari and several other planets we have yet to see in film format.
I'm curious what GL is gonna create, and I'm looking forward to it :)