Firmware Version 1.1.0 incorporates the following improvement.
1. Supports the AF assist beam features of the new flash, Speedlite 270 EX, which is scheduled to be released in April 2009.
Version 1.1.0 firmware is for cameras with firmware up to Version 1.0.9. If the camera's firmware version is 1.1.0, it is not necessary to update the firmware.