"Christmas Carol Week" on 'The Colbert Report' wrapped up last night with Mavis Staples joining Sean Lennon and Wilco's Jeff Tweedy for a version of the John Lennon/Yoko Ono holiday classic 'Happy Xmas (War Is Over),' complete with backing from the Harlem Gospel Choir.

Not only was it the end of "Christmas Carol Week' -- it was also the end of the production year for 'Colbert,' which will take the rest of 2012 off. "We wrote a book, held a music festival, passed 1,000 shows, rigged our campaign finance system, ran for President and was ... named a Senator," Colbert said, recapping the show's 2012, his last line inflected as a question. It also was a big year for musical guests, with Bjork, Jack White, Regina Spektor and of course, the impossible-to-forget Morrissey among the many artists making appearances.