Honestly, as nice it would be to have a SZ in Springfield, I almost feel like it would be a bad idea congestion-wise. You've got a show right there in Castle Theater, you've got dining options right there in Springfield, you have the Terror Tram entrance, Simpsons ride, & Lower Lot...
While I wouldn't mind seeing something clown/carnival related due to Krustyland being right there, I just thing it would end up causing more of a clusterf**k in that area which is already going to be somewhat busy as it is. I see us getting 5 SZs (entrance, Baker st, French st, Lower Lot, Metro sets) like last year. Maybe we will get lucky though and they will put a SZ in Springfield.
The only thing is, adding a 6th SZ does nothing to help with crowds. Another show (or two) & another Maze is what is needed, but neither will happen without some type of sacrifice.