I wonder if they'll do the Hobbit they way Tolkien meant it to be? As a story written and narrated by Bilbo based on his adventure rather than just show the adventure.
Considering Elijah Wood is in this, as well as rumours of Ian Holm, I think we are going to see the story being told by Bilbo to Frodo, or maybe even by Frodo.
I think I would prefer it if we didn't see Frodo, only heard his voice. I mean, how could they explain him looking 10 years older than what he did in LOTR?? The same goes for other supposed cameos like Orlando Bloom and Christopher Lee. They can't get away from the fact that they look 10 years older.