Check out our public beta offering of System Center "Remote Managed Services" by registering here:
http://www.microsoft.com/systemcenter/sce/sceremoteit.mspx
One of our partners (ClearPointe Technology) presented last week to partners on how to deploy and use Operations Manager 2007 with Essentials 2007 to remotely manage multiple customers.
Check out the recorded presentation by John Joyner (ClearPointe Technology) - its full of demos and details!
http://www.msreadiness.com/attendeeregister.asp?eid=5013&rid=378873