Apparently, there is more interesting stuff on the Osama tape that wasn't shown on al-Jazeera:

Officials said that in the 18-minute long tape — of which only six minutes were aired on the al-Jazeera Arab television network in the Middle East on Friday — bin Laden bemoans the recent democratic elections in Afghanistan and the lack of violence involved with it.

On the tape, bin Laden also says his terror organization has been hurt by the U.S. military's unrelenting manhunt for him and his cohorts on the Afghan-Pakistani border

Can't imagine why al-Jazeera didn't decide to run those segments...

Update: In light of the above, here's a rather amusing take on the tape from The Guardian:

Bin Laden, master of propaganda
"...The truth is that Osama bin Laden is very good at what he does. He is one of the great propagandists - up there with Himmler, Lenin, Napoleon and Louis XIV. He has an awesome understanding of the holy triumvirate of political communication: the power of the image, the message and the deed. And he understands how they work together..."

Last time I checked, "masters of propoganda" didn't issue videotapes highlighting their enemies successes...