After the initial announcement
(which apparently didn't go according to schedule), Microsoft have finally formally announced
Gears of War 3 for 2011:
Developed by acclaimed studio Epic Games and available only on Xbox 360, “Gears of War 3” plunges players into a harrowing tale of hope, survival and brotherhood that will conclude the current story arc for “Gears of War”. With the last human city destroyed and the remaining survivors stranded, time is running out for Marcus and his comrades as they fight to save the human race from the jaws of extinction.
A trailer accompanies the release, which you can watch locally on AusGamers
. Our game page also features some newly release screenshots