That would be anytime from October to December next year, which isn't too bad. Far Cry 3 is said to be leaps and bounds (a far cry?) from its predecessors.
Life in the surrounding environment is a major focus in the new Far Cry, as is vastly improved AI for enemies and drop kicking that silly 'weapon durability' mechanic. Check out the E3 2011 trailer for Far Cry 3 below which releases on Xbox 360, PS3 and PC.