Rove & Libby: Perjury or Obstruction of Justice?

It appears that Rove and Libby are having some difficulty keeping their stories straight:

Two top White House aides have given accounts to a special prosecutor about how reporters first told them the identity of a CIA agent that are at odds with what the reporters have said, according to people familiar with the case.

Lewis "Scooter'' Libby, Vice President Dick Cheney's chief of staff, told special prosecutor Patrick Fitzgerald that he first learned from NBC News reporter Tim Russert of the identity of Central Intelligence Agency operative Valerie Plame, the wife of former ambassador and Bush administration critic Joseph Wilson, one person said. Russert has testified before a federal grand jury that he didn't tell Libby of Plame's identity, the person said.

White House Deputy Chief of Staff Karl Rove told Fitzgerald that he first learned the identity of the CIA agent from syndicated columnist Robert Novak, according a person familiar with the matter. Novak, who was first to report Plame's name and connection to Wilson, has given a somewhat different version to the special prosecutor, the person said.

Libby, 54, didn't return a phone call seeking comment.

Will someone be frog-marching soon?