The latest government estimate of flow rate from the current spill is 12,000 and 19,000 barrels per day -- orders of magnitude less than the worst case scenario BP said it was prepared for.
The 2009 plan document puts the volume of an uncontrolled blowout at 300,000 and 162,000 barrels per day respectively, for two wells in the Mississippi Canyon block of the Gulf. (The 162,000 figure is for block 252, where the Deepwater Horizon rig was drilling when an explosion occurred April 20.)
The 2009 document can be read here (.pdf, via the Press Register of Alabama).
For more on BP's oil spill response plans, check out this monster 2009 document submitted to MMS that outlines BP's Oil Spill Response Plan for the Gulf region.