I am upgrading our active directory from Windows Server 2003 R2 to Windows Server 2008 R2. I feel we should just do a simple upgrade by adding the new server as an extra domain controller and demoting the older one. However, our senior developer feels we should build a new active directory from the bottom up. Although this does sound like a decent idea, we have an exchange server in place and I am unsure as to how doing that will impact the exchange server.
What would be the best course of action?