Caroling with the Prez Barack Obama seems to enjoy a good sing-along. He stretches his pipes once again for "Christmas in Washington" (7 p.m. Friday, TNT) with professional assistance from Mariah Carey, Miranda Cosgrove, Andrea Bocelli, Annie Lennox and Matthew Morrison. Ellen DeGeneres hosts because, as she quips, Oprah Winfrey is in Australia.

You talkin' to me? He's hosted "Saturday Night Live" and served as the first guest on "Late Night With Jimmy Fallon," but Robert De Niro has never sat down with Dave. That changes when the Raging Bull makes his inaugural appearance on "The Late Show With David Letterman" (10:35 p.m. Friday, KARE, Ch. 11). DeNiro is usually a terrible guest, but he's bringing along some support in the form of "Little Fockers" co-star Dustin Hoffman.

The long goodbye Jimmy Johnson didn't make the cut, which means someone else will go home with $1 million after the three-hour finale of "Survivor: Nicaragua" (7 p.m. Sunday, WCCO, Ch. 4). We already know of at least one other loser: The old vs. young format, which shouldn't be repeated. Ever.

Life with mother The highly anticipated premiere of "Teen Mom 2" doesn't arrive until Jan. 11, but those who can't wait to catch up with former "16 & Pregnant" participants Kailyn, Chelsea, Jenelle and Leah will be pacified by "The Girls of Teen Mom 2" (9 p.m. Sunday, MTV), which may help explain why these young women are becoming as popular (and annoying) as the stars of "Jersey Shore."

NEAL JUSTIN