The PC market is in decline but still huge. Windows 8/RT will have more total users than Android tablets within a few month. The idea that companies aren't going to build for the default interface is silly.
But how dedicated to the default interface are they really going to be? I imagine there is going to be a lot of developers who decide that if they have to re-write their app anyways, it makes more sense to port it to the web than to port it to metro.
Really doubt it (about Win8/RT having more users than Android, ever), Smartphones are already selling more than PCs. Windows 7 took 2 years to reach 500 millions, and Android is already on that many hands (counting only OHA devices, ignoring Amazon/Nook/China Androids), will be on 1 billion by middle next year.
