Heard last night that they're going to close down a few blocks of Market to test it out as ped/bike only... Which is fine with me. No one in their right mind drives Market on purpose and there's never been any parking there anyways.
They've been trying to get that as a pilot for years. There are often more bikes than cars on Market, and I think it kind of makes sense...especially if it speeds the MUNI surface vehicles up a bit. For that matter, I'd LOVE to see further segmentation of east-west streets for different purposes:
Market Street for bicycles, streetcars, and busses
Mission St for motorcycles
Howard St for cars