He's pushing up daisies
Christopher Hitchens tells us in the odious Mirror, Why I Think Bin Laden is Dead:

Until two years ago, you could hardly shut Osama bin Laden up. He had a great fondness for the sermon, the proclamation, the taped fatwah. And all of these, like the captured video from Kabul showing his gloating over the World Trade Center, were extremely easy to authenticate. Indeed, they were too genuine for my taste. How likely is it that such a loquacious character would manage to sit out the whole Iraq war without feeling any need to orate?

And the recent tape, supposedly from the goat botherer?

It would be easy enough for his fellow-gangsters to prove me wrong. All they need to do, next time they point a video at their heroic guru, is to put in his hands a recent edition of an Arabic or Pakistani or Afghan newspaper. The date needn't be visible - the headline would do.
...
The voice-over seems to be that of Ayman al Zawahiri, one of the few uncaptured lieutenants. It is he who intones the usual jihad rant while his boss walks silently over some landscape. Why so shy, big guy? Cat got your tongue? Figure it out for yourself: it's a lot less risky for bin Laden to pose for an authentic picture, whether still or video, than it is for him to make even a local telephone call. (His deputy Hambali, recently grabbed in Thailand, was caught by using a phone-card.)

Yet this simple piece of photographic propaganda seems beyond him. Even the dullest and cruellest kidnappers know that, in order for their extortions to be taken seriously, they must produce what is known in the trade as "proof of life" before they can blackmail the relatives.

Bin Laden is only being asked to give proof of his own life and he can't even manage that.

In summary: his people badly want to prove that he is still with us. What they want to prove is easy enough to demonstrate. And they can't do it. Whether by induction or deduction, we can infer for now that there's a good case for saying "Hasta La Vista, Binnie".

Maybe he's just pining for the fjords?

And the best line about the "usual jihad rant" was Mark Steyn's:

Instead, Osama makes audio cassettes, and he licenses his subordinates to make audio cassettes, and they issue bloodcurdling threats against everyone from the Great Satan to hapless bystanders like Ireland and Canada, and none of those threats comes to pass. They’re all turban and no jihad.

Kinda like fleas. While mildly laughable, you still call the exterminator.