SF is a unique city on the west coast. It would be a travesty to let a bunch of out-of-towners come here for a few years, complain loudly enough to get their changes passed, then leave a barren and soulless modern wasteland once the boom dies down. Dont do radical expansion during a boom! The south and south-east bay will look like Detroit in a few decades, dont let it happen to SF.
Of course the politicians wont help. Brown and Newsom were so greedy/ambitious respectively, they would probably have loved to work with the tech crowd. Lee achieved what he set out to do the day he was elected; he will now most likely look to consolidate his financial situation and his power. I dont think theres been a mayoral candidate since Jello Biafra who has actually cared about the city itself.
Some of the problems SF would have if density increased significantly: -public transportation is made a for a much lower density than other big american cities. That wont be fixed until bart turns into a comprehensive subway system, which isnt happening while the state is broke. -highways and their off-ramps in the city are made for a much lower density city. -The zoning laws for big-box stores and (i think) grocery stores is pretty restrictive. That will need to change. Which is pretty significant. Maybe we dont want SF turned into SJ/LA?
My personal suggestion would be to impose a severe, severe congestion charge within city limits. This would help to separate the wheat from the chaff, but also to keep services in line with population. The problem is that city leaders are making so much money from tourism and the boom (and potentially development) that they have no interest in helping the city.
The hippies moved to haight because it was cheap and that was all they could afford. The techies moved to SF because it is a first world playground that hadnt been used up yet. Well congratulations, youll get there.