Two movies? It’s a pretty small novel compared to the LOTR books, this means we’ll have to wait awhile after the first one to see Smog! Preposterous.
At least we won’t have to endure any more scenes with Arwen (I hope).
In Hollywood, you can see smog any time you like.
Have no idea if this is still the idea, but originally, THE HOBBIT novel would be the first movie, and the second would be a "new" movie made up of material pulled from other Tolkien sources as a bridge between THE HOBBIT and LOTR.
Again, may have changed, but that was the original plan.