An article in press from PNAS has a rather definitive model of where different fractions of hydrocarbons go after release from deep sea incidents like the Deep Water Horizon disaster.
A Daily Kos Gulf Watchers background of current developments is available in this diary.. An entry point to the scientific article for the lay public, with a good graphic, is here. Or to go directly to the PNAS paper (pre-publication) which can be found here. Ongoing coverage of the disaster from Real Science containing MSM and BP spin is here.