Firmware is at this link - released 19 June

http://www.usa.canon.com/cusa/professional/products/professional_cameras/digital_slr_cameras/eos_5d_mark_iii#DriversAndSoftware

Firmware Version 1.1.3 incorporates the following improvements and fixes.

1. Supports the single focal length EF40mm f/2.8 STM lens that is to be released at the end of June, 2012.

2. Fixes a phenomenon in which an image may become underexposed when using the Auto Lighting Optimizer for continuous Auto Exposure Bracketing (AEB) shooting.

3. Fixes a phenomenon in which the backlight of the LCD monitor may not turn off depending on the camera settings and timing.

4. Fixes a phenomenon in which the camera's power may not turn on when a super-telephoto lens (#1) is mounted to the camera with an extender (#2).

(1) EF 300mm F2.8L IS II USM / EF 400mm F2.8L IS II USM
(2) Extender EF 1.4X III / Extender EF 2X III

5. Corrects mistakes in the Dutch, Italian, Korean, Norwegian, Polish, and Swedish menu screens.