If I understand the situation correctly, lifting the ban on offshore drilling wouldn't have had that great of an effect on the price of gas. If someone said that they were going out to a spot marked "X" on the map to drill for oil, it would be several years before any oil from that site (if any was found) would make it to market. Most of the reason oil prices shot up to nearly $150 a barrel is rampant speculation. I don't understand all the technicalities, but a lot of the loopholes that led to the runaway prices were closed some time over the summer, which is why we saw the price of gas fall to where it is now.
It's nice to see the price of oil fall. Unfortunately for my wife and I (we own an apartment building where we include heat in the rent), we locked in a price for oil during the heating season based on what the price was back in May. It's a back breaking price of $4.55 a gallon. And because of that, our oil company is saying that we can't change the deal.