When people use less and less their PCs they are less inclined to buy newer ones in the future. When it's time to replace my mom's PC, I doubt she'll need more than a small HDMI plug sized Android device connected to a large screen.
Some people, who don't use computers extensively. But most - are using both, PCs and mobile computers. Current interface of mobile devices isn't comparable and can't possibly replace PC ergonomics (keyboard, monitor and etc.).
Real alternative would be some holographic interface that pops out in the air from a computer a size of a grain. That's an alternative to PC ergonomically. Not the current day tablets or handsets.
For many activities you don't need to replace PC ergonomics. Take store clerks for example: the work they do (looking up products, inventory, processing payments) can be done just as well or better using a touchscreen device with a specialized interface.
For some you don't need them, but for some they are a hard requirement. It means they aren't going to be replaced by tablets. Tablets can take some percentage of activities that used to be done on regular computers - that's true. But not all by any means. Therefore talks about "killing" - are not to the point. When some revolution in the interfaces will happen, and new methods will replace keyboards mouses and wide screens - then one can say the classic PC is obsolete. But that time is not here yet.
No, this can't replace keyboards and wide screens because of incomparable productivity. More like holographic screens and input devices which can take a size of a big monitor (or bigger) and offer convenient interaction methods, while not taking really any space.
A PC is not only about ergonomics - and Microsoft's strength is not based on that. It's based on computers with lots of Microsoft software installed that's tied to lots of locally stored data that make moving to a competing platform more difficult.
My mother has very little data on her computer and all of it could fit on a USB stick with ease. I'll bet she is closer to the typical PC user than anyone on HN and that is why PCs, as we know them, have very little future beyond a niche.
Key factor here is ergonomics of computer's interfaces that humans use. The size of the computer itself is much less relevant. It can be a desktop, a mobile computer, a super portable tiny computer. But the human interface is more or less of a constant, given that we, humans, tend to have certain physical parameters which aren't changing despite any technology advancing.
That's why computers with keyboards and wide screens aren't going anywhere, until other real alternative human interfaces will be developed. Touchscreens are good for what they do, but they are no substitute for keyboards, mouses and wide screens by any means.
Are you a writer creating your next magnum opus? Or student who rushes to finish some course work in time? Try doing it on the touchscreen. Are you creating some music or videos? You won't exchange your wide screen editor with tons of controls for any degraded touch screen experience. Are you a developer who uses IDE? Forget about touchcreen tablets - keyboards and monitors are your friends. Are you a hardcore gamer? You won't give up your keyboard and mouse and your high end GPU/CPU for any tablet for sure. And etc. and etc.
What I'm trying to say, is that tablets interfaces aren't replacing regular (i.e. classic PC) interfaces such as keyboards, mouses and wide screens. They are only complementing them. So all this talks about tablets killing PCs is nonsense.
Have you heard of iA Writer for the iPad? Many writers love it and favor it over a laptop keyboard. I also have hardcore-gamer friends who nowadays spend hours playing games on a touchscreen. I think you're being a little narrow-minded in thinking that a physical keyboard and a pointer device you hold in your hand are the holy grail of human interfaces.
Yeah, try playing some latest RPGs like Witcher 2 and etc. on a touch screen. Comments are welcome ;)
Those who need fast typing won't exchange keyboard for a touch screen ever. I didn't say touch screen isn't useful. But it's not a satisfactory replacement for older technologies like keyboards. It's just a useful addition. Replacements will come later.
