Microsoft has greater strategic depth. Windows 8 is going to bring the fight right to Apple's core market, but Microsoft's core market (Desktops) isn't going to be effected. Apple's problem is they've built their house on a pack of cards, which can easily collapse on them. Microsoft's house is built on PCs and their hold is strong and pretty much unbreakable.
When it comes to mobile platforms people don't really care what OS its running. All they care about is ease of use and that it does what they want it to. Windows 8 will provide that, and probably at a more reasonable price than Apple's offerings. This is why Apple is going to lose in the long run.