The Week In Radio: It's sad to see the sun set on Wogan's world

Breakfast, as anyone who interacts with games kit or sleep-deprived teens will tell you, is a delicate time. Nerves are raw, the tempo of the day is still to be set and the slightest irritation, like burnt toast, or Gordon Brown saying "I feel the pain of families" on the radio, has the capacity to provoke out of all proportion. Some listeners enjoy being jolted into their day with a scrap about Conservative party selection procedure, but most others will say 'take me away from all this'.

Those opting for the head-under-the-duvet approach to current affairs have found a home in Radio 2's Wake Up to Wogan which is Britain's, and in fact Europe's, most popular breakfast programme. Getting away from politicians is only a small part of the appeal, however, because Wogan's programme involves not just disengaging from current affairs but frequently disengaging from reality entirely. Now, in its latter days before the arrival of Chris Evans in the New Year, Wogan's fantasy landscape, with its mini-dramas and its comic characters, is more surreal than ever. Even this week, auctioning prizes for Children in Need, there is something almost Joycean in the rambling, esoteric narrative, punctuated by hilarity, the delight in wordplay and names – the Totty from Splotty, Alan "deadly" Dedicoat – the wilful refusal to distinguish between the real and the imaginary. A Martian tuning in would be flummoxed. Is that person emailing from Vietnam who wants to learn Welsh real, or a figment of Terry's imagination? With a self-defined audience of TOGS – Terry's Old Geezers – who communicate incessantly with the Togmeister, Wogan achieves a level of interactivity that BBC suits dream of. During some exchange about The X Factor last week, one of them described the studio audience as "completely mad" and you couldn't help thinking, "hello pot, meet kettle".

As Wogan demonstrates, more than any other part of radio, the breakfast show has the ability to become a part of the listener's internal world. People may describe themselves as Radio 2 or 3 or LBC listeners, but it is the breakfast show with which they most identify. And now the breakfast tectonics are shifting. Alongside Terry's departure, questions are being asked about Chris Moyles's future at Radio 1 and John Humphrys, the mainstay of Radio 4's Today programme since 1987, has only a year left on his contract.

So far, Today has managed the tricky segue between presenters well. Justin Webb has the patrician unflappability of the hospital consultant, while a genuine, civilised kindness distinguishes Evan Davis's bedside manner. Yet admirable though this gentlemanly behaviour may be, Today needs its weapon dogs too. Evan Davis's interview with Gordon Brown about Afghanistan was a case in point. Because it is impossible not to glaze over when Gordon Brown is monologuing – the inexorable monotone, the incessant use of bullet points ("there are three things that are necessary"), the abstract nouns – "burden sharing", "conditionality" – most interviewers feel the need to raise the tempo. Yet despite mounting anger over the war, Davis's tone was of a polite nephew humouring a dull uncle. His interjections had a civil servant ring to them – "It sounds awfully complicated... " or "It's a bit odd, isn't it?" – rather than the acerbic "come off it, Prime Minister!" Humphrys would have delivered. Whether this was a deliberately kid-glove occasion, or whether the PM declined a cage-fight with Humphrys, who knows? But when Humphrys departs, many listeners fear the programme could talk softly without carrying a big stick.

By chance, John Humphrys asking "Would you like a turn?" featured as one of the Questions That Are Never Asked on the new series of I'm Sorry I Haven't a Clue. The choice of Jack Dee to take over from the lamented Humphrey Lyttleton was an inspired one, even if his first joke about Jacqui Smith's husband destroying her career "single-handed" did sound a lot like the News Quiz. Fortunately, with the help of panellists like Barry Cryer and Graeme Garden, the programme's unique flavour remains. Like Wogan's world, the "antidote to panel games" depends a lot on the surreal, the in-joke, and the trick of being risqué without being offensive. New games like Pensioners Film Club ("Death in Fenwicks" "The Postman Always Has to Knock Twice") mixed with old favourites like One Song to the Tune of Another. The sound of Rob Brydon singing the words of Jim'll Fix it to tune of "Mad World" made me choke with laughter. The problem with in-jokes though, is that people get them too quickly. At one point Jack Dee had to issue the howling audience with a plaintive reprimand. "I have got punch lines... please wait."