There are a number of benefits using Exchange 2007 i.e.
you can configure resource mailboxes
more storage groups
wipe-out feature to remove the data from your handled device
better management console
tight integration of PowerShell, explore it what can you do with this which is not possible with GUI.
different roles can be deployed on different hardware boxes
secure than ever
What you don’t have?
So far I’ve known is that Public Folders are not support by default since Microsoft is pushing the collaboration. Collaboration using Sharepoint.note: If you are using Outlook 2003 with Exchange 2007 then you must checkout first before deploying it.