That's 167 million acres in total across the eastern seaboard, according to the New York Times.
Add that to 130 acres in Alaska, and you've got yourself some serious oil production. Drill, baby, drill!
UPDATE: Parts of Florida are also included in the areas Obama wants to drill along the eastern seaboard. Drudge points out that this is a conflict with what he expressed during his campaign. I don't care what he promised during his campaign. Drill, baby, drill!