All the comments about H2 efficiency and explosive risk completely miss the point. Hydrogen fuel cell vehicles have been feasible for years, there have been a few Honda Clarity and Mercedes B-Class FCVs driving round Southern California (which has the ONLY public refueling stations in the entire USA) for several years.
The problem is demand. If you care about the environment you plug in for your regular commute. You can can already buy a plug-in hybrid for half the price and lower running costs than these 2015 cars. As Volt owners gleefully report, most drivers travel for hundreds of miles recharging at home, but for long trips the car has the quick refueling of gasoline that's available everywhere.
There's a market of people who don't want any tailpipe emissions and can't plug in and regularly drive long distances and live near the handful of H2 stations and are willing to spend a lot of money on a new technology, but it's vanishingly small!
Eventually fossil fuels could be so expensive or restricted that H2 will be the range-extender we use for our plug-in vehicles, if ethanol from biomass doesn't work out. But that's a long way away. Meanwhile Toyota and Hyundai are very cagey about whether you can plug in their HFCVs; it seems the answer is No. Their cars have a battery and motor so plugging in is the cheapest way to drive the first few miles, and I think soon consumers will reject a motor-driven car that you can't plug in. The comparative reviews of the first HFCVs against 2015's plug-in hybrid cars will be brutal, and there will be dozens of "gotcha" pieces, wherein the brave reporter drives out of Southern California and gets stranded.