Gearbox, which helmed the PC port of the first Halo and is wrapping up the WWII shooter Brothers in Arms: Hell's Highway (PC, PS3, 360) and the maraca-shaking music game Samba de Amigo (Wii), recently teased it was working on a "big" project.

"It's big. It's, like, look-at-our-line-up-and-imagine-something-even-bigger kind of big," Gearbox president Randy Pitchford wrote on the company's forum back in February. "When you find out what this is, you'll likely agree that I can't oversell this one."

Looking ahead, Gearbox's future lineup includes the shooter Aliens: Colonial Marines (PC, PS3, 360) and the Diablo-like shooter-RPG Borderlands (PC, PS3, 360).

Halo creator Bungie is known to be developing a new game in the sci-fi shooter series, though no details have emerged. Two other Halo titles, Ensemble's RTS effort Halo Wars (360) and a project from Peter Jackson, are in development as well.

Following Bungie's departure from Microsoft last year, Microsoft retained ownership of the Halo property--arguably the biggest and most popular Xbox-exclusive series. At the time, both companies were said to be "focused on the continued success of the 'Halo' franchise."

Meanwhile, the next Xbox--often referred to as the Xbox 720--is expected to arrive in 2012, according to major industry figures.