Sunday on Face the Nation: Countdown to sequester with Sec. Arne Duncan, Sen. Tim Kaine, D-Va., Sen. Kelly Ayotte, R-N.H., Gov. Martin O'Malley, D-Md., Gov. Bob McDonnell, R-Va., Gov. John Hickenlooper, D-Colo., and Gov. Jan Brewer, R-Ariz. Plus: what's the connection between gun violence, video games and mental illness?