I was listening to KCBS a little after 7 AM when the Supreme Court's Gay Marriage 5-4 decision came down--chief reporter, Doug Sovern read the brief and anchor Stan Bunger called the decision, "historic." Indeed.
KGO Radio and KQED immediately went to nonstop radio coverage.
KTVU was the only local TV station that had a reporter in the Castro and provided immediate coverage.
KNTV, KGO-TV, and KPIX relied upon network coverage.
UPDATE 8: 03 PST:
KCBS was the early winner immediately after the decision: the all-news radio outlet had their Friday panel in-studio (good timing) including the Chronicle's Phil Matier and Willie Brown talking about the political ramifications --as usual, it was good radio. Matier offered the theory that the gay-marriage issue would now be taken off the table as Democrat fodder for the 2016 Election, but Stan Bunger was quick to point out that Roe v Wade, after years of becoming law, is still being debated.
The roundtable was both lively and fresh and KCBS stuck to its coverage --while KGO merely read headlines and sent it to reporters in the field.