What we are likely to see if the tapes documenting the interrogation of Abu Zubaydah and Abd Al-Rahim Al-Nashiri are ever recovered is that the "confessions" of the prisoners upon which the White House has built its entire case for subverting the Constitution and suspending civil liberties in this country was obtained through methods such as electrocution, beating to the point of organ failure, hanging prisoners from the wrists from a ceiling, suffocation, and threats against family members ("I am going to find your mother and I am going to fuck her" is one direct quote from a US interrogator). On the missing tapes, we would likely see responses from the prisoners that would be obvious to us as confessions to anything at all in order to end the violence. In other words, if we could witness the drama of manufacturing by torture the many violently coerced "confessions" upon which the whole house of cards of this White House and its hyped "war on terror" rests, it would likely cause us to reopen every investigation, including the most serious ones (remember, even the 9/11 committee did not receive copies of the tapes); shut down the corrupt, Stalinesque Military Commissions System; turn over prisoners, the guilty and the innocent, into a working, accountable justice system operating in accordance with American values; and direct our legal scrutiny to the torturers themselves -- right up to the office of the Vice President and the President if that is where the investigations would lead.
Professor D'Amato called this even before tapes were destroyed.
(I'm assuming interrogations took place, were recorded, and all recordings were destroyed. None of this can really be assumed---what's important is that the interrogations, if they occurred, were likely tainted by torture.)