Justin Timberlake's debut solo project is not only one of the most anticipated albums of the year, it is one of the most well guarded.

The 'NSYNC star has been in and out of recording studios all year, yet neither his record label nor his management will say anything about the record.

Still, the music industry is buzzing and details are trickling out. Most are coming from collaborators — and there appear to be many — but Timberlake himself has spilled a few beans.

Phoning in to Orlando's WJHM-FM last week, he told DJs the album will be out "hopefully this fall." A spokesperson for Jive Records, however, said the as-yet-untitled project is not on their release schedule.

As for the record's nitty gritty, here's what we know:

Behind the boards, the Neptunes are working on multiple tracks, and P. Diddy and his production partner Mario Winans have donated an up-tempo track.

Mike City (Brandy, Nappy Roots), Raphael Saadiq (Bilal, Ginuwine) and Rodney Jerkins (Michael Jackson, 'NSYNC) are also planning to produce tracks for the album, but as of last month none had logged any studio time with Timberlake.

"I just got a call about working on the project," Jerkins said at the BET Awards. "Whenever he wants it, it's done."

As for guest vocalists, two artists Timberlake has recorded with will likely return the favor on his record.

Brian McKnight's manager said he has already recorded with the 'NSYNC star, who appeared on his "My Kind of Girl" single from last year's Superhero, while Nelly has been telling reporters the two friends are discussing another collaboration. Timberlake sings on Nellyville's "Work It" (see [article id="1452878"]"Nelly Collaborates With His Dirty, Justin Timberlake"[/article]).

Angie Stone revealed early in the year that she had been in the studio with Timberlake (see [article id="1451798"]"Angie Stone Makes Studio Time With Timberlake, Moby, Keys"[/article]), and Usher said last month he hoped to log some studio time with him too.

"We're supposed to sit down, have a meeting, talk about it, just creatively," Usher said. "Hopefully, the schedule won't come into play. I know definitely it would be one of the hottest records ever placed out. Ever."

Even if all of the aforementioned artists do end up working with Timberlake, there's no guarantee their tracks will make his album, which is likely the reason his spokespeople have not revealed any information. (BT, not Jive Records, announced his collaborations with Britney Spears for her last album, only to have the material not make the final cut.)

One thing is for certain: Timberlake will be teaming up with all sorts of artists this weekend as Nelly, Usher and McKnight are scheduled to appear at 'NSYNC's Challenge for the Children IV celebrity basketball game on Saturday in Orlando, Florida.