They are in development to turn The Hunger Games into a movie. There's been lots of casting speculation going around but I think they are trying to go with relative unknowns (which is good for this type of thing I think).
I really like all 3 books. I agree that Katniss didn't grow much, but I wasn't really expecting her to actually. I didn't much like the ending though. It seemed too......easy I guess is the word I'm looking for. There were a few times I did want to smack her and scream "wake up!!" but overall Katniss was very resistant to change through the whole series. Prim turned out to be the much more adaptable character.