It depends on what you mean by "creatives." There's a difference between web designers, sculptors and painters. By and large, artists working with physical media have been moving to LA in droves for the past decade. Large studio spaces simply don't exist in the Bay Area at any price - suitable buildings are turned into condos or office space. The situation is similar for NYC artists. Even Jeff Dietch moved to LA, sort of a bellwether for art trends in the country.

For the creatives who stay in SF, the other comment by hugh3 is correct. Most live where you'd expect: the mission, the tenderloin, 6th and Market, etc. Oakland is also popular but not as much as the people who choose to live there make it seem. Artists in SF aren't necessarily living in squalor (or at least any worse squalor than hipster web programmers). My neighbor made a good living painting cartoon robot monsters.