I am not sure if it counts as a cancellation, but apparently Brother in Arms: Furious 4 has been re-purposed into something entirely different.

Gearbox confirmed Furious 4's mysterious fate at a panel during PAX. This isn't the first we have heard of Furious 4 "evolving", but this is the first time we have heard of its drastic change, which includes a name change. When the game is re-revealed, it won't be called Brothers in Arms. Randy Pitchford, president and CEO of Gearbox, promised more details on the new non-Brothers in Arms later this month at Gearbox's community day, which takes place September 15.

[via Kotaku]