Tony Hayward hasn't actually resigned yet but at the present he's not in so good with the Prez and a li'l accident-- a blip, really-- did go down on his watch. Reuters already has a list of fill-ins prepared in the event Big T involuntarily resigns. It includes Andy Inglis (head of BP's core exploration and production division), Iain Conn (the head of BP's refining and marketing unit), and Bob Dudley (a "Managing Director" with responsibility for oversight of the Americas and Asia).
But we're thinking this might be the sort of thing that calls for not just an outsider who didn't work at the company at the time of the event that dare not speak its name but also an outside the box candidate. Names that come to mind include the Alia Sabur (the Long Island genius who says she figured out how to fix the leak in a matter of minutes), Lenny Dykstra (who knows from shit and could just be so wrong he's actually right), Lloyd Blankfein (who most likely orchestrated the "slip up" as a diversionary tactic), and Jack Welch (who's begging for it). Other suggestions welcome.