Hope you don't need to get anywhere in a hurry right now on the Muni Metro. We're receiving reports from the Ex and Twitter (via Muni Diaries) that the Muni underground is running shuttle busses from Castro to Embarcadero, and the inbound track is evidently effed. Also, the J and the N are delayed.
HowFuckedIsMuni.com, however, is only rating the KT and L lines as "probably pretty fucked" right now, and GoogleMaps' touted new real-time transit data isn't giving us anything either.
Update: Jay reports live on the scene: "Muni thing remains a nightmare. Hundreds of people waiting to board shuttles at Van Ness. Metro is outbound only at Castro. Things getting uglier."