I've had a few people email about this, and now the City Paper's City Desk blog has a piece on it -- a street vendor who usually sets up shop outside Speedy Liquor at 14th and Monroe was recently stabbed after an altercation with a man on the sidewalk. Police have arrested and charged the attacker, which is good. Jeff, the street vendor, is out of the hospital.
I think I've seen him around, he usually sells scented oils and plays music on a boom box, and also apparently lifts weights, though I've never seen him do that. Anyway, weird story, and glad the attacker was caught.