This is the unit behind BMW's DPC - Dynamic Performance Control system.
More info on DPC:
BMW Dynamic Peformance Control in Detail http://www.germancarzone.com/bmw-lou...ic-xdrive.html
X6 will be the first AWD model with DPC (aka Dynamic xDrive), while F01/2 7er is rumored to be the first RWD model to come with DPC feature.