I guess I also have to answer this question - For us, the bigger concern is the commute time to the city or east bay if a person works there. Otherwise, gas has not been a giant issue, YET!.
People are more looking into buying more efficient car, appliances, ..etc, as a big picture, rather than concentrating on where to live due to gas price - To be fair, we are also talking about one of the places where housing price is higher than others and a place where people just really want to come and live and are willing to sacrifice other things. .
And Myke - Suburbs are still extremely desirable for a lot of people, all depends on what you need at a certain stage of your life. Where I am, you can enjoy everything S.F. can offer with 1/2 hour of drive (none traffic hours)