Another discussion that I found cautiously optimistic, coming from a renowned skeptic:
http://www.theness.com/neurologicablog/?p=1648
I bet the big businesses using them treat them like a UPS. When a big plant loses power from the grid, they can still keep working and making money. And as someone who lives off the grid from time to time, I'd be into a $3000 unit to keep the beer cold at my cabin. But like the article says, I'd still have to get NG to my cabin, and that's not easy. Wonder if it runs on propane?