With the Dakar horse power restrictions he's said to be giving up the 2 wheel drive trophy truck for a 4 wheel drive set up. The mass HP he puts out is legal in the SCORE series and more than overcomes the 2wd shortcomings... actually better in 2wd for high hp. But with the restrictors they make him employ it falls short of the VWs and Mitsus. Robbie is one hell of a driver - just needs more competitive gear for the race at hand!
It is a Freightliner Argosy, the last year they were made was 2007. There is talk of them coming back out for 2011/12 when they figure out the size of the Dog Box needed with the new 2008-2010 emissions engines. They are really good for Heavy Hauling.
Freightliner still sells new units for the export market, (Austrailia, New Zealand, South Africa, etc.) In fact, they just gave the Austrailia version a facelift. You can still order gliders here in the states though.
If the US ever goes back to length laws, we'll probably see cabovers come back.