This firmware update (Version 1.1.0) incorporates the following fixes and improvements.

1. Adds support for the new Media Transfer Protocol (MTP) USB protocol.
2. Corrects errors in the Simplified Chinese menu screens.

Grab the update at D REBEL XTi / 400D Firmware-E

Updated with Canon response…
Media Transfer Protocol (MTP) USB protocol allow the camera more versatility when connecting to different operating environments. It may be better for the camera to have extra modes like this one, than to not have them embedded in the Menu.