Tonight’s the end of an era as Conan O’Brien hosts “Late Night” for the last time. Next week, he’ll start the transition to L.A., to “The Tonight Show” and to a new hour with a new audience. There is speculation – for good reason – about whether or not O’Brien will be a success at “The Tonight Show”. His brand of humor tends to be a bit irreverent, even raunchy at times. It only takes a glance at his roster of popular “Late Night” characters – The Masturbating Bear, The Horny Manatees, Triumph the Insult Comic Dog – to see his current routine might not go over too well with the 11:35 p.m. crowd.

But O’Brien seems up to the challenge of adjusting his shtick and attracting new viewers. He recently told Billy Bush, “You’ve gotta move, you’ve gotta evolve, you’ve gotta change. And I think the L.A. chapter will be fascinating because man, am I a fish out of water in Los Angeles and man, that could make some good television.” O’Brien takes over the “Tonight Show” on June 1st but still has one more night as the host of “Late Night” making tonight’s episode “must see TV”.

On March 2nd, Jimmy Fallon officially replaces Conan on “Late Night” and he already has a few impressive guests lined-up. His first guest will be Robert DeNiro followed by Van Morrison performing tracks off his classic “Astral Weeks” album. Others guests lined up for Fallon’s first week include Tina Fey, Cameron Diaz, Billy Crudup, Drew Barrymore and Ludacris.

Meanwhile, Jay Leno is preparing for his own transition to 10 p.m. in the fall while Carson Daly’s future at “Last Call with Carson Daly” (which airs at 1:35 a.m. after “Late Night”) lies in the balance as NBC “deals with new budgetary realities.” It will be almost a year before all of the dust has settled from the shake up at NBC’s late night line-up but all in all it looks promising, well, for everyone except Carson Daly.