So maybe this is an end-run around the Saudis and letting things sort themselves out naturally?
"SAMA's net foreign assets totaled $628 billion in November, down from a record high of $737 billion in August 2014,"
The marginal price to produce a barrel of Saudi crude is still the lowest in the world, at just three USD. What's going die out once the equipment is worn out (or require extensive subsidy) are marginal plays in developed countries like Canada, the US, and the North Sea, the Arctic, the deep offshore drilling, tight or heavy oil, tar sands, tar shales, smaller fields without economies of scale, and all forms of biodiesel & ethanol (yes, even the most efficient, Brazilian ethanol).
All the oil-dependent economies are going to suffer and compensate monetarily, by drawing down sovereign wealth or cutting expenditures, but the harder bound is the level at which it makes economic sense to stop drilling. Production prices in the above settings are high enough that they just can't make money at $30/barrel, which is a whole other category of problem than not making enough money to feed the government budget which has ballooned only in the last decade taking advantage of higher prices.
And how much does the House of Saud hand out to its citizens to keep things calm and orderly? What happens when that money starts to dry up?
[1] http://www.wsj.com/articles/new-saudi-budget-expected-to-be-...
[2] http://english.alarabiya.net/en/special-reports/saudi-budget...
This is a traumatic process, sure - but it's not like they were uncomfortably poor 15 years ago, and they (unlike some others, I'm looking at you Venezuela) have plenty of buffer with which to keep their populations comfortable until a few years after their rivals stop drilling.
That's probably the best case scenario for the rest of the world. Cheap energy and keep the amount of money middle eastern countries have to fight each other to a minimum.