Yay, new symptoms. :/
Went to drop off a movie today, left the car idle for 30 seconds. Got back in, drove off, and had a constant misfire for three stoplights, at idle and acceleration. Pulled into a gas station, let it sit for a minute, started it up, and the miss was gone, but obviously the erratic idle was still present.
Stopped yet again to scan the codes, here's what I got this time: