No way that Holder will ever be extradited. Remember that Obama can always pardon him if necessary. The best we can hope for probably is that this will help deny Obama a second term. If he was in danger of being indicted after leaving office, he could resign one hour before the end of his term and have Joe Biden give him a pardon. January 20, 2013: the Day of Three Presidents?
Read up on the power of the Presidential pardon. It's only for Federal crimes, not State crimes or crimes committed in foreign countries. He can not pardon Holder if he's extradited to Mexico.
http://www.justice.gov/pardon/pardon_instructions.htm
http://watergate.info/ford/pardon.shtml
Article 2 - The Executive Branch
Section 2 - Civilian Power Over Military, Cabinet, Pardon Power, Appointments
The President shall be Commander in Chief of the Army and Navy of the United States, and of the Militia of the several States, when called into the actual Service of the United States; he may require the Opinion, in writing, of the principal Officer in each of the executive Departments, upon any subject relating to the Duties of their respective Offices, and he shall have Power to Grant Reprieves and Pardons for Offenses against the United States, except in Cases of Impeachment.
He shall have Power, by and with the Advice and Consent of the Senate, to make Treaties, provided two thirds of the Senators present concur; and he shall nominate, and by and with the Advice and Consent of the Senate, shall appoint Ambassadors, other public Ministers and Consuls, Judges of the supreme Court, and all other Officers of the United States, whose Appointments are not herein otherwise provided for, and which shall be established by Law: but the Congress may by Law vest the Appointment of such inferior Officers, as they think proper, in the President alone, in the Courts of Law, or in the Heads of Departments.