One of the speakers at a panel at the InsideCounsel Superconference was the General Counsel of Johnson Controls. He said with evident pride that over the past 20 years seven people had left the law department and become the general counsel at a publicly traded company. He believes that departures of talented lawyers are inevitable and the step ups reflect well on the training provided the departing lawyer.
It would be an interesting benchmark to look at general counsel produced per 25 lawyers (or some other standard) during the 10 years preceding the count. Successful careers elsewhere are good indicators not just of ability and ambition but also of strong training and good preparation.