It might surprise you to learn that the furry stars of last year's "Alvin and the Chipmunks" movie are celebrating their 50th anniversary this year. But this much will definitely be news to everyone: For the first time anywhere, the overseers of the franchise are revealing their plans for the 2009, um, squeakuel?

" 'Alvin and the Chipmunks: The Squeakuel,' " producer Janice Karman revealed Wednesday, giving MTV News never-before-heard details on the plot, new characters and the A-list star who may not be returning.

"The boys will wind up going to school for the first time — and talk about a chipmunk out of water," laughed Ross Bagdasarian Jr., her co-producer, husband and the son of the man who created Alvin, Simon and Theodore. "That's our boys, and so it's gonna be a really interesting look at a different part of who they are. Christmas Day 2009 — so don't open your gifts, just go right to the theater."

When MTV News first broke the news that an "Alvin" sequel would likely feature the Chipettes, hundreds of fans commented on their desire to see a CG-revival of the singing group's mid-'80s girlfriends. According to the producers, they heard the buzz.

"We're introducing the Chipettes, which are the boys' counterparts," Karman said. "Brittany, Eleanor and Jeannette — we introduced those girls in the '80s on the Saturday morning cartoon shows. Now, they will be in the 'Squeakuel' and create a lot of tension and add a lot of fun and a lot of songs."

Although Karman has provided the voices of the female chipmunks in the past, she said that she'll happily pass the torch to new actresses (rumored to include such names as Drew Barrymore, Miley Cyrus and JoJo). "I think we'll probably get famous actresses," she explained.

"Incredibly fabulous, famous actresses," her husband added, saying that the names will officially be announced soon.

The movie's two human stars, however, might not both be returning — and even more surprisingly, the man who could depart isn't the one you'd expect.

"I know that Jason [Lee] wants to [come back]," Bagdasarian revealed, discussing the possible loss of his new David Seville. "He's got a conflict schedule-wise, because 'My Name Is Earl' is doing a lot of shows through the end of March, and our movie was actually picked up earlier than normal. So we're gonna be coming out Christmas Day next year, and we're hoping he [can] do it. We want to have him in, and hopefully the schedules can work out."

"David Cross is definitely coming back," Bagdasarian said, possibly surprising those who remember the indie-minded comedian defending himself for taking on the role of unscrupulous record exec Ian Hawke. "As you'll recall from the end of the first film, the Chipmunks really dealt him a blow. So he has no money now, and he searches the globe looking for animals who can sing. He finds the Chipettes, and he cannot wait to [make them famous and] get back against the Chipmunks."

Meanwhile, the mischievous chart-toppers with the bushy tails will be found at the beginning of the "Squeakuel" just trying to become normal kids. "They go to a combined middle school and high school, so there's all kinds of [human] kids around them," Bagdasarian said. "You know, kids in the beginning can be cruel, so those first few days are a little bit tough for the boys."

But it wouldn't be a "Chipmunks" adventure if music weren't involved. If fans can't wait 14 months to get their fill of Alvin, they can get a preview with "Undeniable," the Chipmunks' new album that features covers of everything from Blink-182's "All the Small Things" to Bon Jovi's "Livin' on a Prayer." "Because I love some of the songs on this album, I'm trying to get a couple of them in the 'Squeakuel,' " Karman said. "We'll have 'Three Little Birds,' 'The Time Warp' and a couple others."

With production on the "Squeakuel" beginning soon, Bagdasarian confirmed that voice actors Justin Long, Jesse McCartney and Matthew Gray Gubler will all return ("Absolutely!") and added that he is eager to employ the lessons learned after his first foray into live-action/animated filmmaking. "You have very little time, so be funny and be fast."

Check out everything we've got on "Alvin and the Chipmunks."

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