Interesting discovery today.
With Query based Distribution Groups in Exchange 2003, if you send an email to a QDG that you are a member of, you get a copy of the message
With Dynamic Distributions Groups in Exchange 2007 it would seem that is NO longer that case. If you are a member of a DDG you DONT get a copy. Now I have only tested this Custom DDGs so any reader out there let me know if you are seeing this too?