Another one to watch out for is the Mexican Museum Tower (706 Mission). There have been rumblings that a few of the owners in the Four Seasons Tower don't care for the tall building obstructing their views: http://www.socketsite.com/archives/2013/07/an_unfriendly_ult...
Depending on the results of the November ballot, we may be seeing more of these.
I don't know if this is necessarily true, in the same way that if you build an extra lane on a freeway you don't inherently reduce congestion - traffic simply expands to fill the available space.
Many people buying these new apartments and condos will be buying as an investment and renting out, which does nothing to help those in housing need.
Plus, on the margins, it will still increase supply and drop prices, as the price those can be rented out at are driven by supply and demand. Continue to reliably raise supply, and you'll also lower the value of those investments and cause them to sell out as they cease to be good investments.
The reason why that is an attractive strategy in the first place is that demand is grossly in excess of supply. Fix the root cause, the problem will go away.
San Francisco may not believe in market forces, but market forces believe in San Francisco.