2001:
Atwood to Develop Fuel-Cell Power System
Here is more:
IdaTech and Atwood Mobile Products Announce Alliance to Develop Recreational Vehicle Fuel Cell Power System
Although, it would appear their "Fuel Cell" is only being used in the leak detectors currently:
LP & CO Gas Alarm (pdf)
My take: a propane powered fuel cell would be great for an RV. As mentioned by Beacher it could supplant a bunch of RV systems. However, my experience with driving an EV around and reading in EV forums similar to our Thor forum here leads me to believe that they couldn't get it cost-effective enough to work. Fuel cell cars have been "10 years away" now for quite some time (even though Toyota has theirs now just coming out there is only like 3 stations nationwide to fill them up--all in California). There must be something fundamentally too expensive to get fuel cells up and running (yes its the same with EVs, however battery costs for EVs have been falling like a rock lately).