Thanks for the opportunity to speak on this topic.
I agree with many of the comments here.
We have a highly distributed Admin model with central Exchange Servers. We look after the servers and users are managed by their own admins.
Our biggest issue is a perception of a step backwards with many of the features of Exchange 2007. I understand there are probably extremely good technical reasons for these changes but they don't look good to us.
Examples are:
* Attributes no longer visible in ADUC. In Exchange 2003 all the admins in our org can use ADUC to look at (and manage) user properties. Now simple things like secondary SMTP addresses can't be seen in ADUC. A new GUI or powershell (not appropriate!) is required.
* Delegated control. Another tool? Powershell? Assigning mailbox rights requires God level access to Exchange.
* Active Directory OU based functions/features. one exmaple being our use of many dynamic DLs built around areas of the org that are split in the directory into different OUs. Eg. All Finance Staff are under OU=Finance ... All other user properties can be different between users, such as office title, phone, building, department even. Now in ex2007 that type of DL looks like it only accepts address book property attributes being equal to something. We also have dynamic dls for "all users on server xyz" .... how to now?
* Public Folders. gone then back again, partly. Can you access them from OWA? manage them from a GUI. propagate permissions? Even with SP1 management isn't back in the Exchange GUI it is a separate one right?
* ADUC. Has to be mentioned twice sorry. Moving away from it looks like a step backwards. If it is a property display issue with the dialog boxes and the schema will Win 2008 AD bring it back?
cheers