Recently x264 has added 10-bit depth encoding and MediaCoder is keeping up with this new feature. In latest build 4777, new options of x264 have been added, including the High10 profile and 10-bit encoding. With 10-bit depth, video quality can be better at the same bitrate than encoding with common 8-bit depth. However, not all players/decoders support 10-bit depth. As far as I know, VLC can handle 10-bit depth.
Besides, MediaCoder is able to feed frames to encoders in color space of I422, YUY2 and RGB as well as common I420/YV12.