"Tablets and smartphones are the future of computing" to which I say bollocks. If I'm working a 9-5 job and need a computer, I don't want to be two finger tapping on a virtual keyboard. Can you imagine the epidemic of RSI that would ensue. I want a keyboard, a mouse and a monitor, and I don't give a shit what they,re plugged into, but I highly doubt it's going to be a £400 iPad with no access to the file system. I'd rather use a Raspberry Pi if I have real work to do.
Yes, the vast majority of users just want access to Facebook and Twitter, but in business you want a Windows, OSX or Linux PC.
If developers were to actually start developing all iPad apps on iPads I might consider the battle lost, but as far as I'm concerned the PC maybe in decline, but that's to be expected after a boom. It will level out eventually.