So, after ten years and umpteen teases, Smallville has finally come to an end in exactly the way it was always supposed to. In the last few minutes of the finale the Big Guy dons the blue tights and red y-fronts, then flies like the wind, saves Lois Lane, reverses the end of the world, and captures the flag for truth, justice and the American way. For the loyalists who stuck with the show from the beginning, the payoff was surely well worth it. In fact there’s a Royal Wedding/death of bin Laden sense of closure and rightness that makes me feel Smallville will be looked back upon by future cultural historians as one of the defining television shows of the first decade of the twenty-first century – what Dallas and Dynasty were to the optimistic, go-getting 1980s or what The X-Files was to the paranoid but callow 1990s.

Probably the most pleasing aspect of last week’s finale, and yet at the same time a bittersweet one, was the inclusion of the John Williams theme from the movies to play over the closing credits. By now, clearly, the Williams theme is pretty much hardwired into the Superman mythos, and having Superman without those thundering, Wagnerian leitmotifs would be like having James Bond without Monty Norman. In other words Superman now belongs to movie audiences just as much as to the comic-book geeks, if not more so. He really has slipped not just the surly bonds of Earth but also the bonds of the comic-genre that nurtured him.

The English equivalent of Smallville is of course Merlin, a BBC TV-show made by virtually the same people who make Doctor Who and which follows the same “early years” pattern for Britain’s famous magician as Smallville does for America’s Man of Steel. I think the reason it just about works is that Merlin is the character from the Matter of Britain who has retained the deepest and most enduring resonance in our post-imperial age. Just as Superman is a symbol of America the superpower, so Merlin is a symbol of power behind the throne, and of influence by counsel and cunning rather than by direct intervention. The Doctor, in fact, is just one of his incarnations, in an age when even Britain’s more active, physical heroes such as James Bond require subtlety and subterfuge to make up for a lack of cavalry charges.

I read last week that there’s now a new “young Merlin” film in the pipeline. It’s based on T A Barron’s The Lost Years of Merlin series. I’d never heard of this series before, so a couple of days ago I ordered up a second-hand library copy of the first volume from Amazon. It arrived in the post two days ago and I started reading it on the train yesterday morning. Nothing terribly exciting so far, especially as the author promises in his introduction to draw on Irish rather than Welsh myth to start off with. But it may be OK.

Then again, the author is an American, and no American ever lost points for sucking up to Irish sentiment – even when Ireland itself has now been reduced to the ultimate indignity of sucking up to the hated old mother country. Barack’s whistle-stop tour of the Emerald Isle of course came barely a week after Brenda’s historic state visit there, and of course he is enjoying the hospitality of our own green and pleasant land even as I write.

Well, if Cameron’s aim now is to out-blair Blair, why shouldn’t Obama aim to out-dubya Dubya?