It's not open all the way to Treasure Island yet, but you can now bike or walk part ways on the new span. The bike way is named after someone who actually campaigned to have a bike way built onto the new span. Unlike trying to name the span after someone who tried all his might to prevent the new span from being built, in addition to being from the other side of the bay (end of political rant.).
Unfortunately I don't have directions on how to get on the bike way. I hope someone can give directions here, esp. from BART (is West Oakland the closest BART station?).
(Posted to both SF and Oakland forum.)