There would be no purpose served by changing the name of BP while the disaster is occurring. It would have to be after the fact. The American public has short memories but not that short. A lot of people will still not buy EXXON because of the Valdez. When BP bought up AMOCO and a few other things and changed its name to BP in the 90's Beyond Petroleum it still sold a lot of AMOCO gas. It turns out that people thought AMOCO gas was better. (Kind of weird since on any given day all gasoline goes through a lot of the same pipes. A magic additive is poured in and poof AMOCO.) BP probably still owns the name. I would bet that, especially in the southeast, a few BP gas stations switch back to AMOCO. They might all switch and the BP name disappears from the US. Then it can become something else.

If I had a couple of nickels I would buy some BP in August right before the side wells cap it. And if they don't work I would double down after it got knocked down another 50%.