In order to get hydrogen, you have to break it out of some compound, maybe a hydrocarbon, maybe water - and that process takes lots of energy. Then you have to pack it into some compact form, compress it and put it into a strong heavy container, collect it into some catalyst, etc., and that takes more energy. Then the end user has to uncompress it, carrying around a heavy (and potentially dangerous) container, or heating a catalyst to cause release of the hydrogen, taking more energy. Then you can burn it to water and generate energy. (Water vapor is a very intense greenhouse gas by the way. We may not be any better off at all on a hydrogen economy, in any sense.)
I have read that sodium with silica gel or crystalline silicon could create a powder that when introduced to water, creates hydrogen. Also, carbon nano tubes are said to be the answer for the high pressure storeage problem. Researchers are coming at the energy problem from many directions. I think the prospects of limits to the hydrocarbon contribution for the world's energy needs will push research a long way towards a healthy hydrogen economy.