The teaser confirms a few things we were expecting based on past spy shots. The headlights look much more conventional than the Silverado's rather small units. The Sierra's grille, unlike the Silverado's, will also rise above the tops of the headlights, providing more of a big-rig appearance. We also finally get to see the GMC badge on the front of the Sierra, and it looks like it's an enormous rendition.
As for the rest of the truck, previous spy shots have shown the Sierra will have other subtle styling changes from the Silverado. The wheel wells are shaped differently, and the taillights will be unique to the GMC. The interior of the new Sierra will look almost identical to that of the Silverado, with the exception of a few minor trim details. We also expect the Sierra to use the same engine lineup as the Chevy's, which at this point we know will consist of a 3.0-liter turbocharged diesel inline-six, and naturally aspirated 5.3- and 6.2-liter V8s.