It would seem that we discovered the iOS Pocket Edition early! Originally set to be announced at Minecon, the iOS version of Minecraft PE - not even a week after being released - is already the top-grossing app worldwide! Mojang wanted to point out two important things about this version; that updates will be forthcoming, and it is compatible with the Android version!
The iOS version is currently a form of Creative mode, with 36 blocks available to build as players see fit. You can get it in the App Store right now for $6.99 USD. You'll need iOS 4.3 or later to run it properly, and be played both on the iPhone and iPad. Controls are entirely touch-screen based, and quite intuitive. Check it out!