Hey folks,
One of the folks at Makerbot e-mailed me today to let me know that the MK7 extruders were temporarily back in stock (he said they'd added about 30 to the store), and expected them to sell out very quickly. If you also picked up an ORD bot without an extruder, this would be a great time to pick up a MK7 if they're still available when you read this.
http://store.makerbot.com/toolheads/stepstrudermk7.htmlbest,
Peter