My colleague Daniele Muscetta posted a Tweet about how much of OpsMgr is used for AutoPilot. Last year, Michael Isard of Microsoft Research wrote a paper entitled Autopilot: Automatic Data Center Management which describes the technology that Windows Live and Live Search services have used to manage their server farms.
I think that not only OpsMgr is used for AutoPilot but also SCCM and maybe Service Manager. Who knows?
You can find a blog article about AutoPilot on the Dare Obasanjo aka Carnage4Live weblog. If you want more info on AutoPilot just read the white-paper from Michael Isard.