The network said that Leno, who previously hosted the "Tonight Show" from May 1992 to May 2009, would return to the program on March 1.
"We're pleased that Jay is returning to host the franchise that he helmed brilliantly and successfully for many years," Jeff Gaspin, the chairman of NBC Universal Television Entertainment, said in a written statement today. "He is an enormous talent, a consummate professional and one of the hardest-working performers on television."
O'Brien reportedly won't be allowed to take his best-known characters and skits with him when he leaves NBC, but The Wall Street Journal reports that O'Brien will receive a severance package of about $32 million while his staff will receive some $12 million. Staff severance was a sticking point in O'Brien's protracted negotiations with the network, O'Brien's camp told ABCNews.com.
O'Brien is happy with the package but is also supplementing staff severance out of his own pocket with a seven-figure sum, O'Brien manager Gavin Polone said today.
Polone said O'Brien wants to return to the air as soon as possible.
"He's doing so well right now it'd be horrible to lose that momentum," he said. "The numbers are so high and its clearly not just about the controversy."
O'Brien, he said, would want to establish a show similar to the "Tonight Show."
The Fox network has been O'Brien's most vocal would-be suitor, but Polone said no formal talks have begun with Fox yet. He added that there are "other possibilities" beyond Fox but also said that the News Corp.-owned company is "certainly a terrific network."
O'Brien could also explore options with the cable networks or embrace digital media wholly and take his shtick online, the preferred medium for many of his fans: "I'm With COCO," the Facebook group dedicated to the comedian, has more than 500,000 members.
If and when O'Brien does start another show, he'll could have to keep a lid on the NBC-bashing that has helped drive his current show's ratings for the last two weeks: O'Brien's exit package is said to include a "nondisaparagement" clause that would prevent O'Brien and NBC from saying negative things about one another for a set period of time.
One thing that's not in O'Brien's agreement, however, is a rumored "mitigation" clause that would have allowed NBC to avoid paying at least some of O'Brien's severance if he gets another hosting job, according to entertainment gossip Web site TMZ.com.
Suspense is building over how O'Brien will spend what is expected to be his last night at NBC. He all but admitted earlier in the week that Friday would be his final show, joking during his monologue Tuesday night that he was "just three days away from the biggest drinking binge in history."
The show announced that Friday's guests would be Oscar-winner Tom Hanks and comic-actor Will Ferrell, who was O'Brien's first guest when he made his "Tonight Show" debut in June.
Hanks, who was originally slated to appear on the show Tuesday night, posted a message on his Twitter page about the upcoming appearance: "Flag on me with CoCo tonight! Going on Friday's Big Show. What WILL happen? Tune in. Hanx."
Nostalgic fans who will never see the show live can still buy tickets on eBay, where one Arizona-based watcher listed a "Tonight Show" ticket supposedly autographed by flame-haired O'Brien for $6,000. As of Thursday afternoon, no one had bid on it.