Well, I haven't heard anything from the person who I gave my contact info to at the survey so I'm going to spill what I saw for now while I still remember it. Blue_03 can confirm or correct what I write here once he gets a chance to go to the survey as well. If this post disappears in the near future, then you can guess that I probably hit pretty close to the mark.
Before I get into the AV there were two demos there that could have been from any car maker.
The first one was a rear bumper demo. I'm 99% sure this was a Chevrolet product as it was built from the current Silverado bumper. The difference was that in the corners there was a step cut into the chrome portion of the bumper face similar to what's on the cladded AVs today. It really made it a LOT easier to get into the back of the pickup, I definately hope they start selling these soon. If I recall, the surveyor said that the actual price for this option was going to be something like $75-$125. They also had a new "step-side" type assist to get into the bed, but I didn't like it much.
The second demo was a new dashboard which I definately hope is Chevy/GM, but could just as easily be someone else I suppose. First impression when looking at it was Audi-TT with lots of stainless steel circular shapes and black leather everywhere else. Everyone who viewed it said they would expect this type of interior to be in a sportscar, but that it would be a pleasant surprise to find it in a pickup. Two interesting features were the storage areas, and the control knobs. There were THREE glove boxes on this dashboard. One was in the normal position, in the bottom half of the dash in front of the passenger. The second one was immediately above the first, in the top portion of the dash in front of the passenger. The third glovebox was immediately to the left of the first one, on the bottom half of the dash between the first and where the ashtray might be. The control knobs were fairly large (~2" diameter) with a raised black center. In the center were icons that I assume lighted up as you made your selection with the knob. The outer surface of the knob was made of knurled stainless steel (like the handle of a ratchet). There were large knobs like this for the HVAC selections and the transmission (2WD, 4HI, 4LO, etc.) control as well. Overall the controls looked a little more complicated on first glance, but as I got a chance to look at them closer and learn what they all did I started to like them a lot. The transmission control icons looked identical to the ones in the AV today which is what makes me hope this is a Chevy dash, but I'm not sure what the other trucks use there so I'll not hold my breath for now.
Finally, on to the new AV. As I said above, there were three Avalanches at the survey. The first two were Cladded and WBH '03 models and the third was a demo model with no interior at all (there was a piece of black carpeted plywood running across the entire cab at the bottom of all the windows). The question "would you consider buying this model if it was on the lot in 2-3 years" is what makes me think this is the current '06 or '07 Avalanche.
At first glance, the new AV reminded me of a cross between the current WBH and maybe the EXT and definately had a more "street" appearance to it. I thought it was even lowered a little bit (1"-2") but I didn't eyeball across the 3 AVs there so I won't swear by that. I'm going to paste a WBH picture here for reference, but don't get your hopes up too much if you like this look, because although it was similar, there were plenty of differences as well.
The rear end and bed/bed covers of the vehicle were identical to the current AV except for two things. First, all of the chrome portions of the rear bumper were painted to match the body color (which was LPM). The black step pads remained as they are today, just the chrome was covered. Second, there were some posters on the wall showing an AV with a body colored sail-panel and they asked questions about which we liked better. So it's possible that the sail panel will be painted to match the body as well.
The side of the vehicle had three differences from today's WBH. First the handles were painted body color like the cladded AV today. Second, there was a newly designed running-board which tied in tighter to the body lines of the truck than the current one does. Except for the black step pads this running-board was painted body color as well. Third, the rearview mirror was smaller, and oval shaped, wider than it was tall. The front of the mirrors were cut almost exactly in half with body colored paint on the top half and black plastic on the bottom half. Personally I didn't like the smaller oval mirrors at all and the black plastic was really out of place with all the rest of the body colored paint on the rest of the truck. They definately looked like they belonged on a car instead of a truck. The wheels appeared to be ~17" normal Chevy wheels.
Last the front of the vehicle, where there were a LOT of differences. Overall the entire front end was very "smooth" with more body colored paint and almost no chrome at all. One of the guys at the survey said he hated the front and that it looked "like a toad" to him. He was a die hard Ford guy, but most of the people in the survey had some kind of negative comments about the front view including myself. All of the angles of the hood were missing, with a flat line where it meets the grill and I think even the ridges in the hood surface were mostly flattened. The flat hood line also took away the mean scowling eyelids feel that our headlights have today. Seems like the headlights had round lights behind the rectangular clear lens like some european cars but I'm not sure about that. The "power bar" across the middle of the grill was wider and "flatter" as well. It also blended smoothly into the front quarter panels with no break so it made it kind of hard to tell where the side of the truck stopped and the front started. Same went for the bumper which looked similar to the truck above, except without the air intakes. It also was very close to the same width of the truck instead of wider as shown in the picture. Again, it blended in smoothly with the sides of the truck and the grill as well with no break lines so that it made it hard to tell where the side of the truck stopped and the front started. As in the picture above though, the bumper was all body colored. There also was no Chevy Bowtie in the middle of the power bar, but all of the brand emblems were removed or covered up anyway so it wasn't a surprise to see that missing on this demo.
That's about all I can remember at the moment. Perhaps once Blue_03 gets a chance to view and comment I'll remember other details. For now though I hope that gives you a fairly good idea of what to possibly expect to see on the lots in a couple years from now. Personally I hope they take some of our comments to heart and do some tweaking before they release it, including keeping an option for cladding and more of a "work truck" feel instead of the "street truck" that they had to show us.