Been trying to find specific details on this as well. I may not be quite correct with this, but I think there is some degree of traction control betrween right and left wheels on each axle, and the TC sends power to the front or rear axle with the best available traction (less wheel spin, as seen by the wheel speed sensors). If anybody has a better and more accurate explanation of the system, please share it with us.
The good news is that, at least so far in my 2014 with QT2, the system works great in snow. I had a chance to "play" a bit with it a couple of mornings ago. Went up a fairly steep and unplowed hill, stopped, then started moving again and never spun a wheel. Did it a few more times with the same good results. My next test, albeit not totally scientific, will be on the same hill when there is just ice.
My previous WK (2009 Overland with 5.7 and QD2) did this sort of stuff without breaking a sweat; the 2014 is impressive in the snow.
More snow this week... possibly as much as eight inches with slush and ice; I will post the results.