http://www.joystiq.com/2010/11/17/bioware-revealing-new-project-at-vgas-on-december-11/
Update: The sharp eyes of commenter Arth Vader picked up that the gun in the pic is either the M-29 Incisor Sniper Rifle from the Mass Effect 2 Aegis Pack or a reused asset. If it is the M-29, it would imply the game will be Mass Effect related.
Update 2: EA stated last February that something "far-reaching" was coming to Mass Effect in EA's Q4 fiscal 2010, which is between January 1 and March 31 of 2011.
Update 3: Okay, now things are just getting nerdy. BioWare blasted out the adjacent QR code on Twitter which, when decoded, reads: 001101010011010100101110001110000011010000110101. When converted from binary (we told you: nerdy) it reads: 55.845. Of course, as everyone knows, 55.845 is the atomic mass of iron. Maybe the presence of the word "mass" in our findings isn't quite enough to go on, but we're sure you'll agree that the presence of the word "mass" coupled with a piece of fan fiction titled Mass Effect: Iron Rebirth is practically a smoking M-29 Incisor Sniper Rifle.
Update 4: And another QR code has been loosed upon the unsuspecting people of Twitter. This one translates into some binary which then translates into: 128.5°F. Converted to Celsius, that becomes -89.16666666666667 Celsius. "The coldest temperature ever recorded on earth is -89.2 degrees Celsius (-128.5 degrees Fahrenheit) at Vostok, Antarctica on July 21, 1983," says Wikipedia. This Mass Effect wiki page details Vostok, a "a medium system with four planets and an asteroid belt." The Soviet "Vostok Program" resulted in the first manned space flight. Oh, and that asteroid belt it mentions? The wiki page lists it as a "metal-rich asteroid." You know what else is metal? That's right, iron!