All the discussion in the http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/27785106.cfm tread has been interesting. To me, it all boiled down to sure the truck can handle an over-weight camper ...
If we are going by numbers on truck/camper, if the camper has a weight placard of 3000 but weighs 4500 ready to roll are you ok if the capacity of the truck says 3000? ;)
I'm certain, there are other RVs that are overloaded. Obviously, looking way out of balance would be a indicator for police.