Guys, I love MOST of Exchange 2007. But you have completely lost the plot with removing the snap-in from AD Users & Computers. Most helpdesks I've either seen or managed have a very tight and well defined process for creation of users, which is done purely from AD Users & Computers. This includes placing them in the correct OU, adding them to the correct security and distribution groups, modifying any number of other properties, provisioning them for LCS 2005, and- of course- enabling their Exchange mailbox.
So now you introduce a scenario where NO MATTER WHAT you will force these kinds organisations into using two separate utilities (even if they may be within the same MMC)!!! Seriously - take another look at this because it's not going to be popular and you're doing customers a disservice. Helpdesk needs to be less, not more, complex. My suggestion - fix the plugin. Make it work in the same way as other Exchange 2007 functionality, by providing the equivalent cmdlet syntax afterward- fine, not a problem. It really should not be that hard to do, but you would mitigate a massive retraining issue, not to mention seriously reducing the total wasted time ...
On top of this, but related, the fact that there's no means to automatically propagate Managed Folder and ActiveSync policies makes this a major pain in the neck. In all seriousness - you allow a newly create users to receive an email address by default, and when the policy is changed you make it possible to propagate or re-propagate all users matching the policy. This should definitely, absolutely, positively be the behaviour for all policies.
The comeback for issues such as these is the cmdlets. I have no problem with the cmdlets as such - but don't push it onto customers to create and maintain these for common tasks. They should be integrated and consistent.
After all, you want people to like the product, don't you?