I really like that!
One of the problems I see in my company is the "hero" vs. "process" mentality. We don't setup processes that any employee can handle, we just have a few "heroes" who rush in to save the day any time there is an issue. This leads to huge problems when the heroes want time off because we have no idea how they do what they do.
A sabbatical program like this would force a shift towards processes. At least I hope...