As temperatures increase, things happen faster. Bacteria grow and eat stuff faster, chemicals diffuse faster, chemical reactions go quicker, than at lower temperatures.

So, processes tending to clean things up in the Gulf might go faster than they have in Alaska following the Exxon Valdez spill.

There are many factors that could affect positive aspects of this general observation, however, such as effects of dispersants. Still, this temperature factor is just about the only good thing that one can think of here.