Thanks Bourne,
We seem to have gotten in to a bit of a circular discusison so, I'll end it here by pointing you back to the first post in this chain. I think my problem is that I want something I cannot have. I want SSO, dirsync AND I want to decommission my entire Exchange environment and manage my email from the cloud. Call me dense but, I don't see why that's too much to ask for. Thanks for your help Bourne.