I doubt that tablets and smartphones will remain restricted to touch interfaces. I'm not saying that desktops and laptops will whither away while mobile devices remain precisely as they are now. After all, how difficult could it be to make a keyboard or controller that works with a tablet? I've already seen people using independent keyboards with their iPads, and it's only a matter of time before they're distributed more evenly through the market.
Peripherals are fair game, and in terms of hardware, mobile devices are just refinements of the evolution from desktop to laptop. What really matters in terms of usability and popularity are the differences in operating system. The closed garden system, which is easy to deride if you're already accustomed to navigating more open operating systems, is more intuitive and less confusing for most users. And there's no real reason you couldn't play Counterstrike on a closed system, provided the right peripherals. Those peripherals will arrive, so don't let interface issues cloud the advantages. Outside of work, most people simply don't need the big, open systems of the traditional OS native to desktop and laptop machines.