A patch for Battlefield 3 will be released tomorrow, September 20th. The following changes are as follows:

*Stationary and mobile AA cannon damage has been reduced by 30% versus the gunship

*Jet cannon damage has been reduced by 50% versus the gunship

*The delay before moving the gunship forward to a new base in Rush mode has been increased from 15 to 30 seconds

*The Delay between gunship spawns has been increased from 90 to 120 seconds in Rush mode

*Initial delay before the gunship spawns in Rush mode has been increased from 15 to 60 seconds

Source: BattleLog Patch notes