The Samsung Galaxy S II for AT&T is receiving the Android 4.0.3 Ice Cream Sandwich (ICS) update again through the Samsung Kies software. The update was previously released for the AT&T device and subsequently removed citing that it hadn't been properly tested.
Now users are reporting that the update is once again available. However Samsung has still to make an OTA (Over-the-air) update available and any use who wants to savor ICS will have to update the old fashion way – through USB.
Hopefully the OTA update will be available soon.
source – AndroidPolice