It's funny how an average user has NO IDEA about what he actually needs from his computer and how (and for how much money) it can achieve that. Therefore, for the last 3 years the media tells us what we want. First, it was cloud computing, that SUDDENLY became "the future of computing", and it just so happened that no one has ever asked for such a thing. Now it's this - totally, PCs are boring, let's all get a whole bunch of fancy-looking useless underpowered devices each doing a different thing... wait, I thought a single PC can do all those things? Why must I... ah, I almost forgot - tablets are killing the PC market, because you can already custom-build them, install any OS, tweak them, upgrade them, they can run Crysis... wait, what do you mean they're meant for "casual gaming and entertainment"? Why are they killing the PC market, then?
Because it's not the tablets, it's the stupid users who don't need anything more from their computer than a tablet can do. Though, in that case a tablet is still a poor choice - similarly priced netbook will be much better.
To "kill" PC market you need to shut down Intel, nVidia, AMD and a bunch of other companies and shift all the PC gaming to consoles. Sounds realistic to you? No? My point.