We have just release Service Pack 1 for ILM 2007.
This update sets a new base line for future coming updates to ILM with much easier deployment of such updates. The biggest and most important update in this Services Pack is that we now support provisioning of mailboxes on Exchange 2010.
The AD Management Agent now has a drop down box to choose Exchange Server 2010 or 2007. With Exchange 2010 provisioning there MA uses Remote Powershell to connect to the Exchange Server so no need to have the Exchange admin tools installed on the ILM machine.
You can find some guidance on the MA for Ex 2010 on http://technet.microsoft.com/en-us/library/aa998597.aspx. This was written on a pre-release of the Service Pack so might need some minor tweaks but these should be addressed shortly.