Fuel cell technology is not ready for true implementation in vehicles yet, being too costly and too immature as of now. The proof that fuel cells are not ready to be implemented fully is that they're not currently in cars already - there would be no reason to keep using gasoline if they were.
No, technology for fuel cell vehicles is not yet available on a large scale, because the technology is still very expensive. Experts say that this technology will not be practical on a large scale for one or two decades. There are not enough fueling stations available yet to make these vehicles practical on a large scale.