If possible, I would like to see some clarifications for this article...
Microsoft currently recommend to use Exchange servers having all roles, but all of these examples are having dedicated CAS and MBX servers. Is there any reasons for this? When you are using combined server roles, how that affect for the namespace?
Also I would like to see the unbound model where you have two DAGs deployed (across two data centers). Some how I feel that would suits quite many companies with two data centers. And will it change, if you are deploying more than two DAGs across two data centers? (if the DAG goes down, less users are affected).
And big hand for OWA ! That has went log journey with Exchange :D It has been wonderful to see how it has been grown :)