Economically, suburbs and exurbs are not sustainable, as their very existence requires both a thriving metropolitan area and cheap fuel. Well gasoline is not going to become cheaper--although we might save on our long term costs by switching to hybrid cars. But... well I don't want to derail this entry too much by going into the state of our cities. Let's just say that my city, Rochester, gets by... but barely. Also, it is used to wearing a lot of hand-me-downs.
The truth is, off-shore drilling will do nothing to lower fuel prices in the United States when the main force driving up fuel prices is increased demand in the so-called third world (especially since there really isn't much oil off our coasts).