Voice chat is super nice. More iPad games should use it.
I wish some games used voice commands like to select weapons while playing.
"Shotgun" - selects shotgun, then say pistol to select another. Its annoying flipping through weapons trying to find the ones you want in an action packed game, then you die cuz you couldn't find it.
We tried the Xbox 360 Kinect demo at E3 and the voice command is amazing, understood everything we said. Kinect is amazing by the way, makes the Wii feel like a very inferior child's toy.