The ugly, ugly takeaway? A $500,000 safety valve—which BP actively resisted buying—could have prevented this. And now the costs of the spill are estimated to be around $23 billion. And that's if everything continues as is, and the spill is actually capped in two months' time. BP's CEO, Tony Hayward, already admitted that the actual rate of spill might be more than ten times the last estimate—a mind boggling 60,000 barrels a day.
Note the connective tissue in this graphic: the giant black circle in the first bit corresponding to the 1.7 million gallons statistic. Really ties the whole thing together.