Here's the very short Q&A Log from Part 5 of the Labcast Series where folks had a chance to go through the remote Client Access features of Exchange 2007.
Exchange Server 2007 Labcast Series (Part 5 of 8) Questions and Answers Log (03-12-07)
Question: We have a FE BE, single AD Site setup. After we add the first CAS server, can I safely remove the FE server? Are there steps documented anywhere on-line? We plan to have the mailbox role on a separate server than CAS.
Answer: Yes, you can remove the FE Server. Unfortunately, I cannot find any official documentation on how to do this.
Question: should you give me the address that can download the emulator?
Answer: I have the .DESS file for download here: http://blogs.technet.com/haroldwong/archive/2006/06/23/438485.aspx. The Device Emulator files themselves are here: http://blogs.technet.com/haroldwong/archive/2006/05/18/429190.aspx.