These are the first shots we've seen of the heavy-duty GM trucks. From all we've been hearing, the light-duty trucks will come out first, but it makes sense that GM would also get its three-quarter- and one-ton models ready, too.
The frame doesn't seem to be much different, but given the tailpipe, there is likely a new gas engine under the hood. Likewise, with so much camo on the front end, we're guessing GM is experimenting with some kind of active grille and new design. And we're hearing plenty of speculation about a new transmission as well.
Some reports have the half-ton models scheduled for production by summer 2013, with the 2500 and 3500 models coming on-line closer to the end of 2013. That would mean we're likely to see something close to the real thing at the 2013 North American International Auto Show in Detroit, with possible backgrounder events on topics such as powertrain, chassis and fuel economy tech before that.