> allow "a viewer to have the programme content tailored to their taste or mood"
Surely the way to do this would be a combination of features inside the telly?
It would start with image and voice recognition and end up with real-time video editing / substitution. That would allow users (or viewers, in old-fashioned parlance) to choose what attributes the individuals on their TV programmes had. So if they didn't like the voice of a particular "star" they could access a menu and change the pitch, gender or accent (maybe even language, too) of the speech that issues forth from their gob. It wouldn't be a huge step to do the same with the video, so actors clothes could be changed (or removed, or covered up - the "fig-leaf" filter) and themes added. Likewise with their faces and physical attributes.
From the broadcasters' side, this would make complaints a thing of the past. If you didn't like a programme - they it's your own fault for not tailoring it to something more palatable. Offended by the language - why didn't you use a *beep* filter?
For the users, the possibilities are endless. Not only could you substitute Her Maj. in to do the weather forecast, but you could buy add-ons and customisations and maybe even third party mashups and reworkings.
However, the best feature would be that there would never be the need to make an original programme ever again. Gone would be repeats in the orthodox sense. Yes, it would still be Dad's Army (special centenary anniversary edition) but Captain Mainwaring could be replaced with Arnie, Corporal Jones with Catherine Tate's Lauren and so on ...
Of course, you'd never be able to trust a news broadcast - or any other factual programme, ever again. But the downfall of democracy is a small price to pay for a limitless supply of crappy TV.