CNN’s “Piers Morgan Tonight” is following in the footsteps of its predecessor “Larry King Live,” and having guest-hosts for all of next week while Morgan is in London filming “Life Stories.”

Among those filling in for Morgan: Wolf Blitzer, Glee’s Jane Lynch, Ad exec and NBC regular Donny Deutsch, Rosie O’Donnell and Arsenio Hall. Blitzer will anchor a politically-focused show on Tuesday, with the other hosts covering a wide swath of topics, from entertainment to politics. Blitzer previously filled in for Morgan the evening that Steve Jobs passed away, though the show has never gone a full week with guest-hosts.

“Piers Morgan Tonight” has been tweaking its format recently, including a new segment called ‘Only in America,” where Morgan gives his take on the news of the day.

The party’s still going at the Edison Ballroom in Times Square as the “Today” show celebrates its 60th anniversary. The morning milestone began with a welcome from “Today” frontman Matt Lauer before singer Pit Bull took the stage.

Fourth hour hosts Hoda Kotb and Kathie Lee Gifford were early arrivals, with Kotb (below) front and center during Pit Bull’s set. We spotted NBC News president Steve Capus and “Today” EP Jim Bell working the room, as longtime EP and, later NBCU president Jeff Zucker was deep in conversation with former “Today” anchor Meredith Vieira.

“Today” senior broadcast producer Don Nash, who’s been with the show more than a third of its life — 23 years — tells TVNewser tomorrow’s anniversary program is not to be missed. All former living on air talent — save for Joe Garagiola and Gene Shalit who aren’t able to make it — will be a part of the show. And we spotted many of them at the party tonight, including Tom Brokaw, Katie Couric, (above) Barbara Walters, John Palmer and Hugh Downs.

NBC spared no expense flying in correspondents from other NBC bureaus including Andrea Mitchell, Kerry Sanders, Kevin Tibbles, Janet Shamlian and Luke Russert.

Brian Williams stopped in after “Nightly News.” And we chatted with “Today” anchors Savannah Guthrie, Jenna Wolfe and Amy Robach, here with husband Andrew Shue, and said hello to Willard Scott on our way out. Other “Today” regulars celebrating  included Jill Rappaport, Martha Stewart, the Scotto family and Bobby Flay. We chatted with Andy Cohen (mostly about NeNe Leakes) who later tonight will be interviewing Rosie O’Donnell on his Bravo show, “Watch What Happens Live.”

Rounding out the crowd: Willie Geist, Jeff Rossen, Martin Bashir, Carl Quintanilla, Andrew Ross Sorkin, Tyler Mathisen, MSNBC president Phil Griffin and CNBC president Mark Hoffman and many more I may have missed. Because, as I said, the party is still going. Then, tomorrow at 7am, “Today” takes the party nationwide.

Andrea Mitchell and Jeff Zucker

Kerry Sanders and Jenna Wolfe

(Photos: Chris Ariens)

Hoda Kotb and Kathie Lee Gifford did something on the 4th hour of NBC “Today” show yesterday that most people are not used to seeing on-air talent do: hosted their show without any make-up.

“Just before the show I felt uneasy because I kept thinking of two words — HIGH DEF,” Kotb tells TVNewser. “Then after we got rolling, it became liberating. We felt free! (It was either the no-make-up or the cocktails, not sure which.)”

But the pair weren’t the only two going make-up-free. Meredith Vieira, Ann Curry, Natalie Morales, Bobbie Thomas, Sara Haines, and Maria Menunos joined them. After that, Kotb said, “We felt empowered.”

The idea was sparked by remarks Rosie O’Donnell had made recently about surgery she thought Kathie Lee had done. O’Donnell also appeared on the broadcast make-up-less, via skype.

“I feel relieved,” Kathie Lee told us after the broadcast. “Relieved that people received in the spirit in which we did it.”

Kotb says they’ve received a lot of great feedback, though Gifford may have her doubts: “The reaction has been all positive but, then again, I don’t know what anyone’s saying behind my back!”

“So glad we did it…and so glad we are NOT doing it tomorrow!” Kotb says.

Here’s the video:

In solidarity with Kathie Lee and Hoda, TVNewser editors Kevin Allocca and Alex Weprin have allowed themselves to be photographed at the mediabistro offices with no makeup today (Photo here.)

Rosie O’Donnell returns to TV next Wednesday, hosting a variety show, “Rosie Live,” at 8pm on NBC. It was last November when O’Donnell was in talks with MSNBC to host a program, which ended up being “over B4 it began.”

The New York Post’s Adam Buckman reports that O’Donnell discussed the near-deal in a telephone news conference yesterday:

We had a deal and it was about to be announced and NBC changed their mind. It turned out to be a blessing, I think, because I don’t know that arguing about politics is really the best use of my talent. And I also think that Rachel Maddow is unbelievably wonderful.

FoxNews.com’s Roger Friedman “guesses” Rosie O’Donnell is going to NBC/MSNBC.

Johnny Dollar has the audio

“My guess is that she will get a daytime show on NBC with a package deal to do a night-time talk show on MSNBC.”

“What she wants is a daytime show with a night-time show mixed in. The night-time show will be on MSNBC, and it will be a very liberal show, and during the morning she’ll be the happy, friendly Rosie.”

Friedman writes since O’Donnell left “The View” on May 25, the ABC talk-fest has lost over 400,000 viewers.

>An emailer wonders: “Could this take the place of Scarborough Country if Joe Officially begins Morning Joe?”