He was out of work a matter of hours? Rick Kaplan, who announced his exit as executive producer of the CBS Evening News with Katie Couric on Tuesday, has been hired as executive producer of ABC’s This Week with Christiane Amanpour.

ABC News president Ben Sherwood announced the hire today, describing Kaplan’s mission as a bold one: “to lead This Week to #1 and to guide ABC News to dominance in the 2012 elections and beyond.”

Mediaite has learned that Rick Kaplan, executive producer of the CBS Evening News, is leaving his post. Kaplan announced his departure in a meeting with staffers of the Katie Couric broadcast. “You have all made my life for the past almost five years fabulous,” Kaplan said, according to people close to Kaplan.

Shortly after news of the Letterman scandal broke (you may recall that it was broken by intrepid reporter David Letterman), Nikki Finke theorized that CBS wouldn’t investigate it because CBS boss Les Moonves and his boss, Sumner Redstone, had both had adulterous affairs, and so they wouldn’t be too keen on digging into Letterman.

But as the New York Observer‘s Felix Gilette reports, CBS will be looking into the sex-and-extortion saga the way they know best: with a crack investigative reporter.