"Will it be mandatory after Prop 64 passes?"
With prop 215 you have an option to register with the state and even after prop 64 passed it will still be voluntary. If you do register with the state you will need to give the state your personal information however you will be represented by a number which in theory anonymizes you to outside parties. Registering with the state in the coming years may have added benefit due to a tax exemption you will receive which may incentivise people to do so.
pamelahadfield
