Hydrogen was a dead-end when it was proposed. The whole idea of a hydrogen car was nothing more than a distration to hide the reversal of CAFE standards and all the slashes in research into technologies that would actually have made a difference these last 7 years. Fuel cell technology is still out there and ongoing with many promising developments (and commercial applications), but don't look for it for cars anytime soon. With electricity so cheap and available, there's very little incentive to use hydrogen and every incentive to continue with plug-in technology.
The biggest problem is that hydrogen still isn't a primary source of power, just a means of storing it- either way you cut it, batteries or hydrogen or flywheels or supercapacitors, etc, we need about 120 new nuclear power plants to generate the juice required.
These battery packs can be quick-charged at electric filling stations, too, in as little as 15 minutes. Not as fast as filling up a gas tank, but enough that normal people might consider driving a 300-mile pure EV on trips further than 300 miles.
Re: the gas tax. It doesn't have to be on gas, you know, they could get road maintenance in other ways, like income tax or sales tax or any number of things. They could just raise the rate to compensate and chock it up as a sort of EV subsidy. With $12/gallon gas at that point, what's another 15 cents anyhow, right?
