This isn't just a Mock the Week festive special - it's a piece of comedy history. Frankie Boyle has already resigned from the panel in a blaze of bile because he feels that the show - and the BBC - want to cover "celebrities meeting meerkats" rather than real news. Here we'll see how much of the sting is left in his tail as he gives one final seasonal turn - and whether, as they review the best moments of the MTW year, they'll include that Rebecca Adlington comment.

Beforehand there's more reason to feel fearful for the future of BBC comedy, as Clive Anderson puts a Christmassy twist on his Funny Side Of format - which tends to animate quite ordinary clips with clunky commentary and lacklustre talking heads.

Jack Thorne, the lead creator of Cast Offs, has a mission statement for the taboo-breaking comedy drama in which six disabled people take up a Survivor-style reality TV challenge: "To get away from the usual patronising division of most disabled people on screen into 'acerbic or tragic'." Ushered into existence by writers of Skins, Shameless and The Thick of It pedigree, and reinforced at script-writing stage by the experiences of its disabled cast, there's no reason for mission unaccomplished, right? But here's the rub - and it's possibly an easy trap to fall into when you're trying to smash taboos - last night's opener felt so heavy-handed that acerbity and tragedy ran through it like SodaStream bubbles.

If the main message was that disabled reality TV contestants can be just as odious as "normal" reality TV contestants, that was certainly achieved (although blind Mikey from Big Brother 9, with his vile shoutiness and nose picking, has already blazed that trail).

Filmed in mockumentary style, each of the six episodes focuses on one of the castaways. Last night we learnt that kindly Dan, recently made paraplegic by a car accident, was just as likely to be bullied on "Spastic Island" (their words) as by his wheelchair basketball team-mates back home. In flashbacks his chair-bound buddies stole his pants; now his reality show peers desert him, sans chair, on a dark beach after skinny-dipping, just as he was feeling at home with his new self. How could we not feel wretched for him?

The "comedy", alas, wasn't skilfully done. Deaf Gabby smited Carrie, a dwarf, for having a mouth too small to lip-read - but so often that it lost any comical smack. A clumsy layer of crude was then poured on; "little lips" becoming one of the show's many too-easy euphemisms. Surprisingly, the writing became even more clunky when they tackled disability head-on: Dan used forced lines such as "old me, new me, f*** me" to describe his post-accident chagrins.

Its darkness, silences and quiet asides did much more to build genuine poignancy. Moments of Dan's backstory were reminiscent of The Street - when a girl came home with him despite his wheelchair, his dad bobbed around with meerkat-on-Ritalin curiosity. This quietly delivered the message that disability is as much about people around you coming to terms with it as coming to terms with it yourself.

Some lovely lines flowed when the focus drew away from disability. Dan's dad recounted that Dan's accident happened when he lit a fag; his mum interjected, all motherly: "I didn't even know he smoked." The less we confronted the castaways' physicality, the more intriguing they became. Deaf Gabby was most amusing when she was just the dappy-girl-on-reality-TV, saying things such as "I like fire". Will drew us in by being ignored at the campfire - not by being thalidomide-affected.

Perhaps it was a mistake to start with Dan, who is more explicitly tragic because he's still adapting to his own disability, so nice that he makes others look mean. Perhaps Cast Offs just isn't well-written enough to fulfil its goals. Perhaps it's me as a spectator who is still too self-conscious, not sure whether it's OK to laugh at synchronised wheelchair dancing. Wherever the awkwardness lies, I'm intrigued enough to watch tonight's episode, featuring blind Tom. Hopefully Cast Offs will grow more of the courage of its apparent conviction, and let the characters farther transcend their disabilities as it moves away from this harsh first-episode initiation.

The award-winning sitcom The Inbetweeners screeched towards the end of their second series. Two of the leading lads dropped their AS level revision in favour of futile skirt-chasing. For another, playing games-console footie constituted studying (it was PE, right?). The fourth, nerdy Will, drank so many energy drinks that his bowel exploded during his exam.

A series that finishes by trotting out poo puns - Will's mates called him Brad S**t and the Bumlog Millionaire - may not sound like an award-winner, and I'd be surprised if this second outing is as well decorated as the first. But the show is no more puerile than many "adult" (in its purest sense) comedies, and between the bog-standard stuff there were more surprisingly crisp lines: "Women are like fairground rides," advised one of the boys' dads: "F***ing mental."

However, much of the teen awkwardness is so accurately observed that it's almost hard to laugh. Spending more time colour-coding your revision timetable than you do on studying; your mum popping upstairs with some squash when you're entertaining your latest crush; the euphoria of getting served at the pub on the last day of school... such innocent storylines tap into such a huge angst pit that I could hardly watch: I was back as Alex Hardy, 6B, mortified - having finally realised how daft my backcombed fringe really looked.

Al Murray - the world through the bottom of a glass

All hail Al Murray: he hasn't flinched from populating his TV sketch show with folk as fruity as a gay Nazi in pink PVC - even if he has been accused of gay bashing, not least in a scathing Times review.

The ladies behind this new all-girl sketch show - Alice Lowe, Sarah Kendall, Barunka O'Shaughnessy and Clare Thomson - have earned their stripes around some of the best: their comedy CVs include shows with Mitchell and Webb, Steve Coogan and the Little Britain boys. Here they extrapolate events from pop culture - the girls scallywag about as four Russell Brands and there's a what-they'd-really-say take on Sex and the City. They then add in everyday moments with a surreal veneer - should you go on a date dressed as a duck?, etc. A few bits of nostalgia and poignancy may raise smiles, but Beehive is otherwise a punchline-free zone.