I know I'm not the first to mention, but it would be really good if they rethought iOS for the iPad or at least implemented some new ways of handling it.
The other day I played around a Win 8.1 tablet for a while and while I must admit that there were some annoying things and deficiencies, application/window managemant is much more intuitive/pruductive than that of the iOS...
Guys, admit it, this split-screen multitasking thingie is pretty cool and useful. Period. If Apple were the first to come up with this idea, we would all end up in cheer. I also like the idea that a physical button is not at all needed to control the OS. Yeah, I know that there are gestures on iOS too, but they are rather cubbish. I don't want to touch the screen with 4 fingers just to reach the app switcher, and I sure as hell don't want to pinch the screen with all of my fingers just to go back to the home screen... You know what I mean... these things might seem good at first but they are not that good in real life. I loved how I could handle WP 8.1 fast and elegantly without having to fumble about on the screen. Microsoft got this pretty right.
Don't get me wrong, I'm an Apple fan, I love iOS, but imho a device as capable as an iPad would need something different.