What evidence is there that the description of events on this tape is real?
I think all the information on this tape (names of hijackers, their places of birth, etc.) was pieced together from FBI reports and from what has appeared in the media. Is there anything new, or is there any respect in which the facts as given differ from those which we have been believing? (For instance, the FBI could have gotten a place of birth wrong. Or al-Qaeda could have gotten one wrong. In any case, there would have been some differences, if they weren't relying on the FBI and the Western media as their source.)
There is strong evidence that there were other hijackings planned for 9/11 which were thwarted due to the grounding of all aviation. This isn't mentioned on the tape -- in fact the very opposite is implied (with bin Laden holding up a finger for each hijacking, only going up to four). There is strong evidence that many of the hijackers were traveling on false identities; the false identities were used on the tape, even though the individuals involved are dead and need no further protection.
Moreover, I think that the individuals who are listed without a place of birth are the same ones as those for whom no place of birth is listed in the media accounts after 9/11. I haven't gone through the names in detail, so there might be some exceptions here, but a casual perusal does indicate this.
In short, I think this description of bin Laden and his cohorts on 9/11 is probably pure propaganda. And there's no great surprise in that.