But any sense of loss must surely be tempered by a sense of anticipation of what the HBO production powerhouse will come up with to replace it.
HBO - responsible for among others The Sopranos, Six Feet Under, The Gathering Storm and Band of Brothers - has been the saviour of many a British scheduler. As the UK's home-grown sources of comedy drama seem to have temporarily dried up, HBO's products grace virtually all of the UK's TV channels.
HBO programming is most evident on Channel 4, which also uses first runs of HBO series such as The Sopranos to encourage multi-channel viewers to sample its digital E4 offering. Explaining Channel 4's reliance on HBO, June Dromgoole, the channel's controller of programme acquisition, says: "Channel 4 and HBO continue to have a strong relationship because as broadcasters we share similar values for innovation and creative risk."
HBO, or Home Box Office, launched in November 1972 and is a division of Time Warner Entertainment. It provides two premium-TV services to US subscribers - HBO and Cinemax - which are the mainstay of its business.
According to MediaCom's director of international media, Fraser Riddell, these two channels have 38 million subscribers, making it by far the largest paid cable network in the US. And US subscribers don't just get a continuous loop of The Sopranos - HBO operates 15 channels of movies and original programming and is the biggest supplier of boxing programmes in the US.
But it is only in recent times that HBO has become a household name in the UK as it exported its product. "HBO has invested in writing and is canny at developing a niche. HBO has funded stuff that is different from the rest of the market," Riddell points out. Indeed it has, and the stuff it has funded is just what UK TV companies and audiences alike are after.
The man pulling the HBO strings is its chairman, Chris Albrecht, who took over control of the company in the middle of 2002. During this time Albrecht, who has been described as an old-time studio chief, has steered HBO to further commercial success with earnings in excess of $800 million - a considerable sum to HBO's ailing parent company, AOL Time Warner.
But, by training, Albrecht is not a numbers man but rather a creative type. He was a talent manager looking after stars such as Jim Carrey and Whoopi Goldberg before joining HBO in 1985 to expand its use of series in programming. It was Albrecht, as executive creative, who realised the potential of series such as The Sopranos (which had been rejected by every other studio) and of Sex & The City.
His elevation to chairman of HBO last year shows the faith that AOL Time Warner has in its creative hotshot.
Jeff Ford, the director of acquisitions at Five, argues that Albrecht is merely following a tradition of innovative television at HBO. "They've always had a belief in themselves," he says. "HBO is producing lots of good stuff and it has proper network budgets to do this."
The majority of HBO's product reaches our screens via arrangements with Warner Brothers and Paramount. As a US subscription cable network, international distribution is not its key business.
While HBO, perhaps by default, has been extremely successful in attracting young upmarket audiences in the UK, Ford says some of the HBO product is very American and will not be shown here. Arliss, for example, an HBO comedy drama about a US sports agent, is unlikely to grace any terrestrial TV channel's schedule.
While the demise of Sex & The City and, indeed, The Sopranos (which is unlikely to go into a sixth series) may be a loss to viewers, there is a list of new contenders to take their place. HBO has just started airing a police drama called The Wire in the US while its comedy Curb Your Enthusiasm is also set to hit UK screens some time in the future.