The only reason water powered cars are not being developed is that it's free to power it and no one is going to pay off a politician for something thats free. Ever seen the movie Chain Reaction? Pretty much sums it up!
Electricity is not free and I haven't heard what the impact is for an all electric car on your household electric bill!
I do believe that big oil companies influence if not control our government. I hope the Leaf works and can be mass produced to sell for close to the price of a subcompact. Problem is that buyers of subcompacts are not the target market for electric cars. I think the Chevy Volt is a bunch of GM propaganda. Ford is the innovator and they are on the fence with their money.