The problem with OPEC and all the other big oil producers is that they're addicted to $100+ oil prices and the income it generates. Something like 80% of Iran's economy is based on oil exports. Now that they aren't getting the big bucks they and all the other exporters will cheat on the quotas just to keep the money coming in.
IMHO, oil has dropped in price partly due to the global economic slowdown reducing demand but primarily due to all the speculators pulling their money out of the market. Remember the Saudis telling us $147 oil was due to speculation? Seems they were right.
I figure oil will go down more, a lot more, just long enough to kill off any efforts to switch over to some other type of fuel. Then it will drift back up again and the addiction cycle will continue. Just like it did in the 70's and 80's.
These whipsaw moves in prices will mean headaches for everyone's economy, users and producers alike. You can't make a business plan without being able to plug in a valid cost of energy, and if you can't make a business plan, you don't have a business.