Photo: HBO

Why Cannes? Because it's a mosh pit of the high-profile movies that you're going to love or hate throughout the year. In a rare turn of events, Americans have already had the opportunity to see the opening night film, Baz Luhrmann's lavish "The Great Gatsby." The buzz is all about whether the elite Cannes crowds will crow as Leonardo DiCaprio and Carey Mulligan own the red carpet only to dismiss the moneymaker as an exercise in materialistic excess? Cannes audiences are notorious for their candid reactions. Boos and hissing are as common as standing ovations.

Meanwhile, stars swarm the upscale French Riviera mecca once frequented by "The Great Gatsby" author F. Scott Fitzgerald. Stars will also splash the big screen, including Ryan Gosling, Justin Timberlake, Marion Cotillard, Clive Owen and Matt Damon.

Among the high-profile participants, American director Steven Spielberg will head the prestigious jury, which includes Nicole Kidman, Christoph Waltz and Oscar-winning rival Ang Lee. They're tasked with choosing from 19 films in 12 days for the prestigious Palme d'Or. It's the ultimate networking exercise and a sweet spot for Spielberg. After last year's losses he returns to the festival that screened his debut feature, "Sugarland Express," in 1974.

Here are a dozen reasons why Cannes matters:

Tobey Maguire and Leonardo DiCaprio in 'The Great Gatsby' (Photo: Warner Bros. Pictures)

When Baz Luhrmann announced that he would helm "The Great Gatsby," with Leonardo DiCaprio playing the title character, it was a buckle-your-seat-belt moment in movie history. Could the Australian director of "Moulin Rouge" finally pull off the literary adaptation of F. Scott Fitzgerald's classic about the American dream, a vision that has eluded so many before him?

Well, after much delay, fanfare, and cross-promotion, it appears that Luhrmann's $104.5 million 3-D adaptation is in serious trouble. Here are the 10 reasons why we think "The Great Gatsby" may be the summer's first great disappointment.

We have a feeling you'll be hearing lots more about Ty Simpkins after "Iron Man 3."

Starring as Harley Keener, the 11-year-old fifth-grader serves as the pint-sized straight man for Tony Stark's best one-liners while helping the fallen hero repair his badly damaged suit.

Despite Simpkins's epic Hollywood résumé -- "Insidious," "Revolutionary Road," "War of the Worlds" -- he still attends public school. We caught up with him after school and got the lowdown on his key role in the summer's first blockbuster.

Penn Badgley in 'Greetings From Tim Buckley' {Photo: Tribeca Film/Focus World)

The serious and soulful side of Penn Badgley, 26, emerges in "Greetings from Tim Buckley." He plays singer-songwriter and guitarist Jeff Buckley, the son of Tim in the movie's title, which opens in limited release today.

Badgley's lead performance as a musician living in the shadow of the famous father he barely knew, shows a depth, range, and vibrancy to the actor, who also sings and strums all by himself. Badgley has fond memories of the experience he gained playing heartthrob Dan Humphrey on "Gossip Girl," the show that boosted him to stardom and a regular spot on the tabloid stage. Now, he's ready to blaze new paths and escape the comfort zone of series television. During the Tribeca Film Festival, Badgley discussed how becoming Jeff transformed Penn.

Photo: Charley Gallay/Getty Images

Ty Simpkins shares more screen time with Robert Downey Jr. in "Iron Man 3" than Gwyneth Paltrow. The eleven-year-old Hollywood vet ("Revolutionary Road," "Insidious") plays Harley Keener, the kid who helps Tony Stark pull his suit together after the superhero falls to earth one snowy night in rural Tennessee. Simpkins told Yahoo! Movies his five favorite films, and it's no surprise that "Iron Man" tops the list:

Trine Cyrholm and Pierce Brosnan in 'Love Is All You Need' (Photo: Sony Pictures Classics)

Pierce Brosnan might have turned in his license to kill, but that's not stopping him from talking Bond, James Bond.

Yahoo! Movies caught up with the 59-year-old actor in Manhattan to discuss his latest starring role, in Danish filmmaker Susanne Bier's charming romcom "Love Is All You Need," opening Friday. The Irishman plays an embittered widower that gets a second chance at love with a cancer survivor (Trine Dyrholm) when they meet at their children's Italian wedding.

But, ever the gentleman, Brosnan graciously switched gears and discussed his years as Bond, where he fit in the 007 pantheon -- and seeing "Skyfall" for the first time.