This is an animation from CNN that shows the oil that is on the surface and how that has progressed over time.
The big question of course is - how much oil is below the surface? And where is all of that? The whole idea of "dispersants" (with names dripping in spin-doctoring like "Corexit") is to hide the mess by making the oil invisible to the public by making it no longer float.
If you look at the frame from June 8 in particular you will notice a large breakaway swath to the south-east, off of the coast of Florida. Where did that go? Did it retreat back to the main mass or did it "disperse"?
What exactly are the effects of 100 million gallons of oil - "dispersed" in sea-water? Is that considered "cleaned up"?