About gyros - AppleInsider
That’s a very well written article; it says: gyro accelerates the game engines in iOS.
I totally agree. Besides being a differentiator, the gyro should also be a gold mine for devs, maybe a bigger one than the accellerometer was.
Just imagine a 3D world handled by gyros and accellerometers…
http://iphone.appleinsider.com/articles/10/06/16/inside_iphone_4_gyro_spins_apple_ahead_in_gaming.html