At one time there was no shortage of bin laden videos but no new ones for a long, long time. Why not?
First, this really isn't accurate. There has never been a tremendous amount of video of UBL. Secondly, and more importantly....when there was video of him, it was prior to us putting boots on the ground and hunting his sorry as$! UBL clearly became much more interested in his well being, staying alive than with promoting his new found status.
Also note, the video of him that came out shortly after 9-11 was not put out by him or AQ propaganda wing....but it was video that was recovered during a US SOF Op and then released to the public. Could there be other such videos recovered during Ops since (be it 2005, 2007, 2008) and simply not released to the public?
Operational security...its easier to smuggle out a audio tape.