Can't people just answer Piggie's question? Lol
There's an awful lot of faith here in Apple's position. Remember, in the tech world, Goliaths can be toppled at anytime, particularly when the David in this instance is a company with the resources of MS.
I think the iPad will continue to see closer integration with the Mac, to the point where one can almost move seamlessly between the two for many apps. I expect much more robust support in iCloud to make this happen.
I also think the iPad will have to allow a better way for inter-app coordination. Tablets aren't PCs, but that doesn't mean they need to be dumbed down in their operation. Apps need to be able to talk each other where it makes sense to do so. Siri, for instance, needs to be able to interact with third party apps to truly unleash its potential. Very basic things like uploading files from Safari cannot go missing in the future. Apple will find a way to address this without sacrificing too much of their sand boxing philosophy.
And, finally, I think Apple will continue to evolve its app ecosystem, whether it's developing its own apps to bring them even closer to desktop-level sophistication or supporting the developer community to ensure that they're all staying with iOS. Windows 8 has a long road ahead of it in getting developers to develop Metro-specific apps (see the relatively lukewarm momentum for Windows Phone). The app ecosystem is one area where Apple enjoys considerable success, and this has to be maintained to stay ahead of the other guys. Windows 8 may or may not be able to build the initial momentum it needs, but if it does it'll accelerate at a very fast pace given Microsoft's ability to scale.