Here in Louisville we have a few Hybrid busses. I'm sure that sooner or later these chassis will be the underpinning for RV's but I doubt it will be less than three years until they show up commonly. I haven't been able to find anyone that manufactures them.

By the way, to all those who've never been to Burning Man, don't take your own vehicle unless you plan on it's death in the near future. The playa dust is very fine and VERY alkaline. It'll eat everything it gets into.