This runs very well on mobile Safari as well. In fact, the frame rate is smoother on my iPhone 3GS than it is on my MacBook Pro.
Edit: After some further testing I noticed that setting any dummy CSS transform boosts transition/animation performance on iOS. For example: -webkit-transform: translate3d(0,0,0)
Edit: After some further testing I noticed that setting any dummy CSS transform boosts transition/animation performance on iOS. For example: -webkit-transform: translate3d(0,0,0)