I didn't notice this until after installing 5.1.1 on my iPad 3 just now, but remember the nice animation you get when you split the keyboard on the iPad? I am no longer seeing the animation part and it just splits. Just curious if Apple got rid of this in 5.1 or did they remove it in 5.1.1?
I just tried to check before doing the update: on 5.1 my iPad 1 did the animation where the keyboard slides up and then (I believe I recall it) sliding apart to the left and right. After updating to 5.1.1 it still did the animation of sliding up to the middle of the screen, but now it instantly splits.
Though I'm not totally sure if I remember correctly that the keyboard slid apart for 5.1 (since I didn't know what I was watching for), I can double-check on another iPad running 5.1. But I'm fairly certain you are right, the left/right animation was removed.