Got an update from my LBS. Seems that while installing a new set of innards sent to the shop by Shimano, the technician discovered that the aluminum tangs as discussed here are the parts that failed. It's adding an additional 4 days to the repair time! It'll be nice to have a new IGH and sprocket, but I've been off of my bike for over a week and a half. This is my primary means of commuting and not having it is a real hassle. I don't think that the bike infrastructure yet supports a car free life. That is, of course, unless you have a backup bike. I don't