Gas prices that low mean the economy is essentially dysfunctional. It means domestic producers can't many money drilling, so they stop, and we end up buying Iranian and Saudi oil instead of American oil. It means commerce is not happening, and the prices of other things gets cheaper, and if we run into a deflationary spiral, we end up in another Great Depression. Granted, a lot more goes into making a depression, but gas/oil prices that cheap is not a good sign.
You should also take a look at how much of that gas price is taxes and how much is actually profit for the refiner and oil company. Profits are not that obscene within the gas/oil industry.
Finally, if you feel pain at the pump driving an E-250 van on a 100-mile roundtrip commute, you may want to consider buying a more fuel efficient vehicle.
