A hydrogen economy is so far off that it's even more fiction than a Tesla. There are at least two Tesla dealerships in the Denver, Colorado area, and these cars are in fact driving around (at least the Roadsters).
First, hydrogen is just an energy carrier. How are you going to produce this hydrogen?
Second, once you produce hydrogen, how are you going to distribute it around? Replace natural gas? Not for hundreds of years....
If you have the energy to produce hydrogen, why not just use the existing grid? Sure, the US electrical grid needs some TLC, but it is quite functional and is capable of serving a significant number of electric vehicles, especially when charged during off-peak hours. We have no infrastructure to produce and distribute hydrogen on any usable scale.