I've been waiting for this announcement and dreading it at the same time.
The approach to the Golden Gate Bridge from Lombard St. and Marina Blvd (Doyle Drive) wil be closed from 5PM April 27 to 5AM April 30 for demolishment.
This would NOT be a weekend to try to cross the Golden Gate bridge by car nor try to get to the south Vista Point. The open approachs (via Park Presidio (Hiway 1) and Lincoln Blvd in the Presidio) are bound to be a mess. I would stay clear of this area in a car.
Anyone considering riding a bike over the Golden Gate that weekend, it should be business as usual.
Afterwards traffic will flow on half of the new Presidio Parkway while the other half is constructed. Final completion is 2015 I believe.