I haven't yet had time to read the DoD memo carefully; real life keeps intervening somehow. But it's hard to imagine I'll have much to say about it that
Michael Froomkin hasn't already said.
Marty Lederman sent me this nifty little bibliography on the legal questions, which I pass along to you. You'll need Westlaw, Lexis, or a law library to find these sources:
John T. Parry & Welsh S. White, INTERROGATING SUSPECTED TERRORISTS: SHOULD TORTURE BE AN OPTION?, 63 University of Pittsburgh Law Review 743 (2002)
John T. Parry, WHAT IS TORTURE, ARE WE DOING IT, AND WHAT IF WE ARE?, 64 University of Pittsburgh Law Review 237 (2003)
Sanford Levinson, "PRECOMMITMENT" AND "POSTCOMMITMENT": THE BAN ON TORTURE IN THE WAKE OF SEPTEMBER 11, 81 Texas Law Review 2013 (2003)
Seth F. Kreimer, TOO CLOSE TO THE RACK AND THE SCREW: CONSTITUTIONAL CONSTRAINTS ON TORTURE IN THE WAR ON TERROR, 6 University of Pennsylvania Journal of Constitutional Law 278 (2003)
Marcy Strauss, TORTURE, 48 New York Law School Law Review 201 (2003/2004)
Alan Dershowitz, THE TORTURE WARRANT: A RESPONSE TO PROFESSOR STRAUSS, 48 New York Law School Law Review 275 (2003/2004)
John Yoo and John Ashcroft, TORTURE, SCHMORTURE: THIS SORT OF KVETCHING JUST HELPS TERRORISTS!, 1 Baghdad University Law Review 55 (June 2004).
(OK, OK, so I made the last one up. So sue me.)