One of the few features that our customers really are missing (when migrating from MS Exchange) is;
1. You can't open up another persons calendar (or email folders) from Outlook using standard functionality (even when using ActiveSync)
2. The booking of conference rooms in Outlook is not implemented (Outlook has an excellent feature for this)
By having an account who is a conference room (able to reply with auto-accept), you could see free/busy info and book it. If you had several rooms - they would be listed by the Outlook room-finder function.
This would close much of the gap between SM and MS Exchange for many users.