Hi Mark,
I stumbled upon your web site while google searching for an upcoming project that I have coming up for a client. BTW, great article on not using the .local for a domain name....very intuitive!
Anyway, I'll make this brief and hope you can shed some light unto this matter that I am dealing with:
My client is on windows and Exchange 2003 with multiple locations, each being on a subdomain. So, there are no root domains. They would like to merge all of these domains unto a single domain as well as migrate to windows 2008.