The timing is great for Obama. He can claim that he is prosecuting the guilty, i.e. BP for the accident. Trials to begin in 2012. The news media will pick this up and you will see it every day in the news along with the fact that it is the Obama administration that is pushing the prosecution. Makes him look good for the green crowd. Domestic corporations will be left off the hook if they play along and donate to his campaign. At least that's what I think.
You have to be naive to think that companies are prosecuted for political purposes. Many times big companies are not prosecuted for political purposes. It takes some fortitude to take on the prosecution of big corporations. Don't forget that.