If it's comic based, one of the three figures can even be Batman, like they did with the Aquaman set.
At least I'm hoping to be a location set! Totally bored of all the vehicles!
76122 batcave has almost the same piece count as 70909-1: Batcave Break-In: 1037 vs 1047. If all the pieces are for the batcave only, we can have some really nice hideout, but I think there will be some vehicle too.
My opinion is almost similar as yours, with little corrections.
Batmobile vs Joker - 3 to 4
Batman and Robin vs Mr Freeze - definitely 3
Riddler heist - 4 to 5
Batcave - max 6, if we are lucky 7 :D
Yeah and they are in stores 2 months before the movie. This is my observation too. I still hope they are hiding it because of plot (spoilers). It will be really sad, if we don't get a set :(