I've seen pictures of the thing during creation.
You put your ATV's and luggage on TOP of it. Looks like its got an 6 ft bed, with tilt capabilities.
The woman on car-seat.org (who posted the creation pics) said you could fit 5 child seats across in the cab.
On the inside, its like a trailer home (but fancier, of course.) Looks like fold down beds, has a whole kitchen and table and everything.
GPS built into the dash.
One-touch fold-down stairway.
Further specs listed on the website. Site is still under construction I guess.