Technically SFMM went 'smoke-free' about 2 years ago. They put up signs saying that there was no longer smoking allowed in the midways/queues/etc. and it listed 3 areas where you could go to smoke.
The signs lasted about 2 weeks, no one enforced the rules and eventually they were gone. They popped up again about a year ago, again lasted for a few weeks, no enforcement, and were gone again!
This is all very interesting to me. After talking to a senior level guy from SFMM last week his quote was "he's got some great ideas and if he can pull them off the park will be amazing, but we all have our doubts that it's possible".
This is what I'm seeing. They have these grand ideas to turn the SF parks into a real nice family destination, but they don't have the staff or the infrastructure to pull it off.