The MsExchange team has blogged a matrix with gui features removed versus reason and how we can do that in the Exchange Server 2007.
As discussed in the earlier blog post introducing the new Exchange 2007 console, the Exchange Management Console GUI has been completely redesigned in Exchange 2007. While redesigning the Exchange Management Console for Exchange 2007, we used specific ground rules to help guide what features and settings should be exposed in the console and how the console itself should be built. These guidelines allowed us to ensure that we had designed a rich, functional tool that wasn't overwhelming and complex. It also ensured a console where additional feature GUI could be added to respond more effectively to customer requests.
Read more at source: http://msexchangeteam.com/archive/2006/11/08/431279.aspx