At some point, the patent wars between Apple and the rest of the world will have to end. Its competitors will find a way to get around those patents. These skirmishes are meant to buy Apple some time, to stunt the growth of Android or even kill it. It's good for Microsoft to say the least. Then what?
Looking at the PC market as a parallel, when the first laptops came out, couldn't the first maker patent that idea and prevent others from producing a competing one with a keyboard with a LCD cover attached to it? The clam shell design?
In some sense, Apple is doing the same thing with the iPhone and iPad. Okay, not exactly the same but similar. Again, competitors will wise up and work around Apple. At that point, it will be Apple who has to answer.
New compelling designs will be out but the key to all of this is going to be iOS. In a 5-6 years, it's possible that iOS and OS X will merge or be virtually indistinguishable. And it'll always be the Apple's control over software and hardware designs and a clear mobile vision that will win the day.