Only two problems with hydrogen.

Support infastructure, and how to produce it at a sane cost without using fossil fuels. By the time we get that second item worked out, we'll have the mass production bugs out of fuel cells and the idea of hydrogen "burning" hybrid will be obsolete.
_________________________
-IronRaven

When a man dare not speak without malice for fear of giving insult, that is when truth starts to die. Truth is the truest freedom.