Those are really sharp sketches,
@AllTerrain. I agree, I'm glad that GMC stayed close to these designs with the finished product. I also am a huge fan of those taillights...I do like the actual tailights too, but these just look cool.
Also (most notably in the second image from the top and the second image from the bottom, but in a couple others as well), I noticed that they tried to incorporate the old Hummer HX Concept grill (the vehicle that was slated to become the Hummer H4 in late 2010) into some of the designs. They had kind of a slotted, recessed look to it. For reference: