I think I know the answer to this, but my boss is questioning that answer so I wanted to check for sure. Currently we're running AD2003 - yeah, I know. In that environment I have each of the FSMO roles assigned to one of two DC.'s. We will probably be upgrading to 2008 or 2012 soon and we're establishing a second data center that will also function as a DR site. So, my question is, as a part of DR does any version of AD support having any one FSMO role living on more than one DC at the same time, or does any kind of replication exist so that if a DC died that was hosting a role that role can automatically be transferred to another DC?
Without looking into any Microsoft materials, the primary reason why this may be a non-factor is because all DC's are, inherently, writable. As such all DC's can act as an authority when clients make requests to them.
The biggest concern is replication.