There is a certain inevitability about the news of the cancellation of Robin Hood. And it’s not just because it follows hot on the heels of ITV’s decision to axe Primeval. Ever since these “second wave” series appeared on our screen, it’s felt like a matter of when, rather than if, they were going to be brought to a premature end. Doctor Who and Ashes to Ashes (in its Life on Mars incarnation) are the shows that inspired this recent fantasy TV boom in the first place, and look as if they’re going to outlive everything commissioned in their wake. Merlin is coming back for a second run, but who’d bet on it making it to series three?