While we don't yet know a ton of details, a new listing has showed up on Amazon which shows a full-priced Family Guy game scheduled for release on September 25, 2012.
Activision is listed as the publisher, leading us to believe this is the Family Guy game that Activision announced back in February 2011.
The full title of the game is Family Guy: Back to the Multiverse, indicating this may be an offshoot or sequel to the "Road to the Multiverse" storyline which featured Stewie and Brian travelling through different dimensions with a remote control.
This wouldn't be the first Family Guy video game though. Back in 2006, 2K Games and High Voltage Software (The Conduit) released the aptly titled Family Guy Video Game!