Hi, I'm new to this forum and like you I am also very interested in the mystery car being tested throughout the US.
As an Aussie, the GM Holden brand is an institution here with the first car rolling off the assembly lines in 1948. The Commodore was introduced here in 1978 and is now celebrating 27 years of production. During the past 27 years, we have had the Commodore built on 3 platforms with the new VE being built on the 4th platform.
So any information about this new platform is real interesting.
The picture of the camo car being tested in the US could look something like the one in the following link (mechanicals anyway). The car pitured appears to be a VZ Commodore mule.
http://www.mtfile.com/ls1/VEorLS2Mule_01.jpg