The nominees for the 53rd annual Grammy Awards won't officially be revealed until December 1. But with the eligibility period having closed on September 30, the contenders are now clear, with early favorites and intriguing storylines already emerging.

According to Billboard's survey of record executives and industry observers, the 2011 Grammys will likely field its strongest and most competitive collection of record and song of the year nominees in recent memory. While this may lead to a Grammy night filled with memorable, over-the-top performances, it's bittersweet news for the industry, as it mirrors the shift in the marketplace away from albums and toward the less profitable commodity of singles.

Many experts project Eminem as this year's potential across-the-board winner, as his album sales remained strong in 2010.

Here's a preview of possible nominees in the four main categories:

SONG AND RECORD OF THE YEAR

Nearly everyone surveyed agreed this was a superb year for singles, especially for pop. There was also consensus that four songs would face off on February 13, 2011, for song and record of the year: Eminem and Rihanna's collaboration, "Love the Way You Lie"; Lady Antebellum's "Need You Now"; Jay-Z and Alicia Keys' "Empire State of Mind" and Lady Gaga's "Bad Romance." "These are all formidable singles," says Warner Bros. senior vice president of digital Jack Isquith, who hailed them as "meaty, impressive, career-defining records."

Other top tracks cited by multiple executives include Train's "Hey, Soul Sister" (eligible for record of the year but not for song), Katy Perry's "California Gurls," Usher's "OMG," Sade's "Soldier of Love," B.o.B's "Airplanes" and Florence & the Machine's "Dog Days of Summer."

Last year, Beyonce's "Single Ladies (Put a Ring on It)" won song of the year, and Kings of Leon's "Use Somebody" took the record prize.

ALBUM OF THE YEAR

In the album of the year category, Eminem's "Recovery" is the clear favorite in a subpar field. "This is Eminem's year," says Billy Mann, who co-wrote and produced last year's showstopping Pink hit, "Glitter in the Air." "He brought his best game and then some. The public can feel it, and the industry can feel it." To date, "Recovery" has sold 2.7 million copies, according to Nielsen SoundScan.

Los Angeles Times chief pop critic Ann Powers says Eminem's comeback story, as well as the fact that his album was both commercially successful and critically acclaimed, will resonate with Grammy voters. "He's a major figure in pop history," she says, "and he seems to have really grown into himself."

Another leading contender is the Carole King/James Taylor album "Live at the Troubadour." While live sets historically have fared poorly with voters (1994's "MTV Unplugged: Tony Bennett" is the last in-concert title to win the category), "I would watch out for that record," Glassnote Records head Daniel Glass says. The album has sold 453,000 copies since its May release.

Other albums cited include Sade's "Soldier of Love," Jay-Z's "The Blueprint 3," Lady Antebellum's "Need You Now," Arcade Fire's "The Suburbs," Usher's "Raymond v. Raymond" and two from recent Grammy winners: Herbie Hancock's "The Imagine Project" and Robert Plant's "Band of Joy."

Powers thinks Sade's album is a strong bet. "It's a gold-plated release," she says. "It sold well (1.3 million copies), it was well received critically, and she's a classy artist."

Last year, Taylor Swift took home the statue for "Fearless."

Two breakout acts, B.o.B and Mumford & Sons, were mentioned on multiple occasions as strong contenders for best new artist, but most believe it will be a battle between Drake and Justin Bieber, with Drake taking the award.

Emerging stars Nikki Minaj and Bruno Mars are ineligible for nomination this year, because their album release dates fall outside of the eligibility period (September 1, 2009 through September 30, 2010) -- in Mars' case, by one week. Other possible nominees this year include Florence & the Machine, who got a big boost out of their MTV Video Music Awards appearance, and reality TV superstars Susan Boyle and Adam Lambert.

Despite the success of Swift and the Zac Brown Band at last year's ceremony, many country observers say this year's crop of new artists is unlikely to garner many nods. Luke Bryan and Chris Young were both mentioned as long shots.

Grammy voters didn't suffer from a lack of options when it came to nominees -- according to Recording Academy president Neil Portnow, the academy received almost 20,000 submissions this year, a new record.

The nominees will be announced December 1 during the third annual "Grammy Nominations Concert Live!! -- Countdown to Music's Biggest Night" concert. The ceremony will air on CBS on February 13.