1.40 features a number of bug fixes, including new terrain and terrain buildings. New sounds have been added and sound bugs have been fixed. New sounds include main gun reloads for tanks and FPS mode. All new map icons have been added and icons in general have been revamped to appear much sharper at all distances. "Death Cam" has been enhanced, yellow flags are gone, "forced exit" on death has been added and there is even an in-game clock.
For in depth details on version 1.40, go to the announcements sections in the forums.