ET has confirmed that "Project Runway" judge and fashion designer Michael Kors is joining the teen ranks of The CW's guilty pleasure, "Gossip Girl," for one hot night this fall. Michael appears as himself during a New York Fashion Week episode the show recently taped.

The witty designer tells Women's Wear Daily that he's a diehard 'GG' fan: "I love the clothes, everyone is good-looking, the plot line is a riot. I love the show. They called and said, ‘You are very 'Gossip Girl.' I thought, 'Finally, I am a teenager.'"

Joining him on the episode are heiress Tinsley Mortimer and Cristina Cuomo, editorial director for Gotham and Hamptons mags. "Gossip Girl" returns Sept. 1 on The CW.

It is only August, but "American Idol" host Ryan Seacrest knows what he will be doing on New Year's Eve. He will return as the co-host of the newly titled "Dick Clark's New Year's Rockin' Eve with Ryan Seacrest."

"The name change of the program reflects the success of the co-hosting responsibilities of one of America’s most time-honored traditions. We are thrilled to extend Ryan’s contract as co-host of the ‘party of the year’ with Dick,” stated Orly Adelson, executive producer and president of dick clark productions.

"Watching 'Dick Clark's New Year's Rockin Eve' is an American tradition," adds Stephen McPherson, president, ABC Entertainment. "Ryan has been a tremendous part of the show the last couple of years and we're thrilled he’ll be part of it for years to come."

The Jonas Brothers will perform on Thursday night's season finale of "So You Think You Can Dance," reports the New York Post.

They'll play their hit single "Burnin' Up."

Nick, Joe and Kevin are coming off a banner night at the Teen Choice Awards, where they took home six surfboard statuettes.

Move over Vince and Ari -- you've got company! Mark Wahlberg is set to cameo on "Entourage," says the New York Post.

"I did one other cameo in the pilot but I didn't get to do a scene with Jeremy Piven," he says, referring to the Emmy winning actor who plays combustible agent Ari Gold. "This time it's me and Piven going at it, so it was fun."

Wahlberg, who exec produces the popular HBO show, will appear during the fifth season, which kicks off next month.

Betty White and the rest of the "Golden Girls" are the subject of tabloid headlines implying that they disrespected their late co-star Estelle Getty by not attending her funeral.

ET was exclusively behind the scenes of "Million Dollar Password" with Betty to get the straight scoop.

"We were with Estelle when it mattered," Betty tells ET. "I didn't go to her funeral and Paul, her wonderful caretaker, knew I wasn't going to her funeral."

ET has confirmed that Lauren Conrad will be joining the cast of "Greek" for the final episode of the hit ABC Family series -- playing herself.

"The Hills" star goes from unscripted to scripted in a tip of the hat to her own MTV series in a storyline that finds "Greek" sorority siren Casey (Spencer Grammer) in a situation similar to one that Lauren experienced on "The Hills" when she had to make a choice between a boy and a job.

A spokesperson for "Greek" tells ET that Lauren appears in a dream sequence, in which Casey asks herself, "What would Lauren Conrad do?" as she dreams that they are bff.

When "The Price is Right" returns for its 36th season -- its second with Drew Carey -- one thing you won't be seeing is the recent "Plinko-gate" game.

It happened last week when a contestant was playing Plinko and did something that had never been seen before on the show. She landed in the $10,000 slot three times in a row.

"This woman couldn't lose," Drew tells ET. "She drops one chip, she wins $10,000. She drops another one, she wins $10,000. She drops another one, another $10,000. The crowd is on their feet, they're going crazy. She drops the fourth one and [the floor director] runs up and he goes, 'No' and he puts his hand out and stops it. And he looks at me and he goes, 'It's rigged!'"

"I am just a mom who is working hard and had a dream and that dream came true last night," Melissa Lawson told ET the morning after she won the "Nashville Star" title and the opportunity to record an album under the auspices of John Rich.

Despite finishing in the bottom two several times at the beginning of the competition, the 32-year-old mother of five boys says, "In the end, it was one of those things I really appreciated, because it helps you not take any single moment for granted. It helped me to really enjoy and take in every moment from then on, because you didn't know if you were going to go home or not."

Winning "Nashville Star" isn't the only life-changing event in Melissa's life. Seven months ago, Melissa weighed close to 298-1/2 pounds.

Kelsey Grammer is doing fine following his recent release from the hospital where he underwent medical tests, his rep tells ET. 

“Kelsey Grammer is out of the hospital, feeling great and about to resume normal activities at home. He and his wife Camille want to thank everyone who expressed concern. They appreciated the kind words,” a statement from the rep said. 

ET broke the news last week that the TV vet was hospitalized in New York less than two months after suffering a heart attack in Hawaii. 

Two months ago, ET's Thea Andrews was on the set of "Samantha Who" with Christina Applegate. It was before ET broke the news that the star of the ABC sitcom had been diagnosed with breast cancer and it was a happy occasion for Christina who was going to be able to dance in the episode that was filming that week.

"I haven't been able to dance uninjured in a long time, so it feels really great to be able to do it," Christina, who earned a Tony nomination for Sweet Charity on Broadway, tells Thea. "It feels really great to be able to do it. I'm really confident that I'm not going to do roll over on it and break it again."

The broken bone to which Christina is referring is her foot. The accident happened during her time on Broadway, but trooper that she was, she returned to the stage as quickly as possible afterwards.

Shirley MacLaine portrays Coco Chanel in a new miniseries for Lifetime, and the veteran star talks to ET about the famous French fashion designer's persona and late-career reinvention!

"She was a woman who had nobody, and maybe on some level her life was destined to be alone and not to be poor again," observes Shirley, adding, "I have a whole Chanel wardrobe now for when I go out in public, so I know how to dress."

Premiering in September on Lifetime, "Coco Chanel" charts the fashion icon in her later years as she set out to re-establish her reputation as a fashion trendsetter after spending years in exile.

Stars attending the "Teen Choice Awards" reacted to the news that Christina Applegate was diagnosed with breast cancer. Among those offering words of support were Sophia Bush, Lauren Conrad and Jerry O'Connell.

Christina was nominated for a Teen Choice Award for her TV show "Samantha Who?" but did not attend Sunday night's ceremony.

ET broke the story exclusively on Saturday that Christina was diagnosed with an early form of breast cancer. A statement from her rep said since the cancer was detected early it is considered "not life threatening."

Regis Philbin and Kelly Ripa join the previously announced list of guest stars for the new season of "Ugly Betty" that includes Lindsay Lohan and Kelly's hubby Mark Consuelos.

The stars of "Live with Regis and Kelly" will play themselves in the premiere episode, airing September 25, when Wilhelmina Slater (Vanessa Williams) and Alexis Meade (Rebecca Romijn) appear on the chat fest to promote the upcoming issue of Mode magazine. It is the first issue of Mode since Alexis fired her brother Daniel (Eric Mabius) and Regee and Kelly put her in the hot seat!

"Ugly Betty" airs Thursday nights at 8 p.m. on ABC.