On the death of the PC, or, at least, small-w windows
This month, a couple of the magazines to which I subscribe presented some challenges to the black box fallacy. February's issue of IEEE Spectrum (p. 23) outlines the views of Jakob Nielsen on Windows 8, whose lab testing of the new operating system leads him to suppose that "Microsoft tried to almost optimize for the mobile scenario, and that’s why their desktop design falls through so bad." APC Magazine's extensive review in November 2012 came to a similar conclusion, albeit without the precision terminology that Nielsen uses to explain his views in the full interview about his experiments. In the March 2013 issue of the same magazine, Tony Sarno's editorial (p. 3) lambasts the view that "the PC is dying", to be replaced by the present fashion for tablets and smartphones.
Now, I suppose that a mobile computing enthusiast might assert that the PC is indeed dying and that Microsoft is therefore doing exactly the right thing in optimising its operating systems for mobile computing devices. More accurately, if Microsoft sees its market as consisting largely of mobile devices (rather than office computers and server farms), then maybe it is indeed doing the right thing for its commercial purposes.
Yet, if for no other reason than the size of the screens involved, tablets and smartphones are surely not going to replace server farms, home theatres, and probably not even office computers in the foreseeable future. Obviously it's Microsoft's own business as to what market they want their products to serve, but I haven't heard the company announce an end to its interest in the PC market, and all of the reviewers mentioned above clearly expect Windows to continue to serve this market. Unless we've all completely mis-understood Microsoft's intentions for Windows 8, it seems that Microsoft may have fallen victim to a form of black box fallacy in which there is one grand unified interface suitable to interacting with all kinds of device, regardless of the device's purpose or form factor.
Considering APC's Future of the PC Poll, however, did give me some first-hand experience with why someone might forget about PCs: they are, it has to be said, pretty boring. I could, no doubt, amply answer the poll's question about what can be done with a PC, but word processing, software development and the hosting of web sites don't much inspire me to "suggest a positive marketing message or slogan that PC makers can use in their marketing". Then again, maybe that's exactly how you'd expect an engineer to answer. I find soap, say, pretty boring too, but my local supermarket still moves shelves full of the stuff.
