I know a lot of factors will cause the fluctuation of diesel as well as gasoline fuel prices. Primarily, the old supply and demand hypothesis will govern the price of just about any commodity.

However, I'm curious if the advent of hydrogen powered vehicles is causing the oil companies to be fearful of their future. I found the MSN video below to be very interesting. I think hydrogen powered cars and trucks are very close to becoming a reality. It also would be great if we could tell OPEC to stick it.

http://video.msn.com/video/p.htm?m=Entertainment&mi=Discovery%20Networks&i=d1c68b14-ee9d-46e9-b126-1be2a48107cc,7aa3af93-bc4a-4ac6-b6f1-cbeb5f051910&p=Entertainment_Discovery&rf=http://www.msn.com/?SU=http://msnbc.msn.com/

You can bet that when hydrogen or whatever else comes in the future to provide fuel for vehicles it will be mfg, distributed and retailed by the same companies now in the fossil fuel business. Two-bit a gallon stuff is history.

Until some good ol' boy drills a hole in his back 40 and hydrogen sprays out, it will remain an energy form, not an energy source.

Right now it's made as a byproduct of refining and olefins production. Any on-purpose hydrogen is made from steam reforming of methane (natural gas).

An asian country has a motorcycle that runs on this stuff. Bad news, it only can go about 30 miles on the fuel it carries. They are trying a new form of fuel cell that heats up, and runs more efficiently, by placing the exhaust system close.

I don't know what the next vehicle fuel will be but I am pretty confident that it will not be hydrogen. Hydrogen has too low an energy density and is takes too much energy to compress to ever be economically viable.

Even if hydrogen becomes more viable, it will be decades before the infrastructure is in place to compete with conventional fuels. Between world appetite for fuel and refinerys running at capacity in the US, don't look for it to go down.