As of right now, Saturday morning, the strike is still back on starting with the beginning of service on Monday (August 17) due to the train operators/station agent union voting down the contract. Could still change....but not looking great.

Edited to add: SAMtrans has announced that the KX bus will add stops so it can be taken to/from SFO and Millbrae BART where you can connect to Caltrain to and from San Francisco. Might well be darn crowded though!