If there is one hard and fast rule in marketing, it is that convergence - the combination of two functions into a single device - never works.
The received wisdom was that we humans developed set patterns of behaviour that we associated with specific products or brand names. Once we had done that, we were unable to cross over to a different way of thinking.
According to the old ways, there is no way a telephone should be a camera. And, as for a computer being a home entertainment centre - unthinkable. Well, not any more.
Today's average PC will link and network every media source in your household, allow you to create, edit and distribute wirelessly and, with terabyte-sized hard drives now commonplace, will store all your different entertainment media without any physical clutter.
The doyen of the new breed of all-singing, all-dancing units is the iMac. Complete with high-resolution screen, its on-board software is geared to encourage users to merge the boundaries between passive reception of entertainment ('I watch a DVD and listen to my downloaded music') and creation ('I edit my own movies and make my own songs').
The additional stimulus of being able to upload to YouTube, plus watch the mix of amateur and professional content on the video-sharing website, takes the experience still further.
Where the idea of 'home computer as family entertainment centre' typically falls down is in the syndrome that computer users tend to work in isolation - not just from the rest of their family but often from the entire world, as any gaming addict will concur.
Since 2007, Apple TV has been able to play digital content originating from any Mac OS X or Windows computer running iTunes on HDTV.
And today all new home entertainment centres - audio, HDTV and the like - include USB slots so that you can transfer your digital media from computer to living room.
The PC or Mac is likely to link directly to the home entertainment centre. That doesn't mean it will replace your 50-inch HDTV screen and sound system, but it might well receive your television channels for you and make your DVD player redundant. In time, the home central computer will be the hub, receiving and distributing all digital media. As such, it could even become a shared experience, rather than the current largely introspective one.
The best news for consumers in all of this is that there are likely to be few, if any, areas of incompatibility among the various digital units.