Why is al Qaeda releasing a second bin Laden video?

There’s another bin Laden video coming out soon. This time, bin Laden will introduce the testimony of one of the 9/11 suicide bombers.

The appearance of a second video is surprising as it is hard to see why after three years off screen bin Laden is making two appearances in a week. One would have thought that the first video reminding everyone that bin Laden is still out there as the anniversary of 9/11 approached would have served their purpose.

It also seems odds that they have sat on this video for so long. One would have expected them to include it with the testimony of some of the other suicide bombers that they released on the fifth anniversary.