(Also awesome would be using the nextbus API to predict when the 1, 1R and 800 are coming at 49th/50th & Telegraph for those of us who use the bus. Also possibly the 12 which is at 51st, I think.)
The plan was to make a system that makes only a few announcement before BART stops running for the night so people don't get stuck here. Do these buses all stop running for the night too? If not then a permanent "next bus/bart" display might be less intrusive than periodic announcements.