It's official, the BP Gulf oil spill has in fact outpaced the Exxon Valdez spill in 1989, according to media reports. In fact, the lowest government estimate is more than double what BP was estimating. 

Reuters has a story on it, but the gist of it is that the federal government has estimated 10,920,000 gallons of spilled, and it could be double that much, though obviously, some has been cleaned up or evaporated.