Evan, I think you may have missed the question here. At least how I read it there was an unanswered question left:
"Exchange said:
Brian,
You still have two options:
1) The easy way – use the powershell cmdlets and it’s all done for you magically
2) The hard way – populate the same attributes you used to do in E2k3, then call the Update-AddressList and Update-EmailAddressPolicy cmdlets to properly provision these objects (sort of like manually invoking “the RUS” in E2k3 terms).
"
Brian had asked about API's and I take that to ask about provisioning from non-windows machines.
"Why would anyone want to do that?" you might ask.
Surprisingly, not everyone runs just Windows for their systems. More and more there are people that need to provision across platforms and want something other than MIIS to do it.
Does this mean that an API that is callable from a non-windows platform won't be available? i.e. purely ldap based provisioning of Exchange? What about ldif? Will that be supported in Exchange 2007?