Greetings and thanks for suggesting this topic.
Although variations on this theme have been around for years, "coaching" for managers and key executives seems to fit well with what people are wanting at this point in time. Perhaps some OD interventions are too complicated, expensive, or of unclear value as possible reasons for a return to the simple and fairly modest in cost notion of coaching. Regular opportunities for consultation with a person who is attuned to a manager's developmental needs and to their current work issues will always find a market.
Personally, I always build this into my OD work such as team building but also have enjoyed a practice of working with manaqers and execs alone, especially when they are in transition. This would be a great time for someone to summarize the literature available on the topic. Anyone interested? Regards, Charlie Seashore