Rihanna 'Birthday Cake' Cameo Will 'Shock The World'

It's one of the most-talked about songs on Rihanna's Talk That Talk, and it's barely a minute long. Now, "Birthday Cake" — 78 titillating seconds of school bells, handclaps and engines gunning — is set to get a full-length reboot. But according to co-producers Da Internz, the featured guest on the remix will be more than just icing.

"We got the Rihanna 'Birthday Cake' coming out in a week," a bespectacled Kosine told on the red carpet of the ASCAP Rhythm and Soul Brunch, held over the Grammy weekend.

"It's gonna be crazy," his production partner, Tuo, said shaking his head.

"And the feature on there is gonna shock the world," Kosine chimed in cryptically.

The interlude (board work by Da Internz and The-Dream) is among the saucier bits on Rihanna's sixth LP, with the titular confection serving as a metaphor for a region of the female anatomy. "I know you wanna bite this/ It's so enticing," Rih sings. "Nothing else like this, I'ma make you my bitch/ And it's not even my birthday / But you wanna put your name on it." A hypnotic chant on the word cake follows.

So would Da Internz offer up even a hint at the identity of this jaw-dropping guest feature?

"Nope, nope, not gonna be on my watch," Kosine said smiling but tight-lipped. "All I'm gonna say is stay tuned — it's dropping [this] week."

Tuo added that fans should also expect a clip for what stands to be an explosive track. "The visual has to go with it because everybody's going to be like, 'Oh my god!'

That left us wildly speculating, tossing around names in the MTV Newsroom. After some thought, we realized that buzzed-about artists who have organic connections to Rih, like onetime flame Drake or Roc Nation pal J. Cole, wouldn't exactly shock us by making an appearance on a Rihanna single. But what about Chris Brown, who was spotted last week exiting the same Hollywood recording studio as his fellow Grammy performer, Rihanna? Rumors quickly began to swirl that the exes were cooking up a duet.

A verse from Brown, the crooner indelibly tied to the Bajan beauty since their relationship imploded after a February 2009 assault? That would be shocking.

Make your best "Birthday Cake" guess on our RapFix poll!