Microsoft's chief software architect Ray Ozzie was discussing smartphones at Microsoft's Professional Developers Conference earlier. Apparently, we just don't get what's important and what's not in the smartphone battle, because according to him, apps don't matter one bit.
All the apps that count will be ported to every one of them. It's a completely different situation from the PC market, where software's built to run on a Windows or a Mac. Mobile apps require very little development, so it's much easier to bring them onto every platform.