Canon EOS 5D Mark II firmware improves video

While I welcome the improvements to the video capabilities of the Canon 5D Mark II, I am curious why the firmware does not also include the ability to shoot at a lower 720 HD video resolution for those times when 1080 is not needed. A lot of the new cameras have this muiltiplel resolutioncapability. Surely this less demanding resolution is not as difficult as going in the other direction.

Dan