No plans on that at the moment. However, most realms are connected in clusters, the biggest being the Firemaw cluster.
This is a tough cookie for us to sell as newbies check era servers and see them all deserted, when in fact they are clustered.
An advantage of this is that you can have a horde char in one server within the cluster and and ally char on another within the cluster and have de facto characters on both factions. Theres a lot of cross faction collaboration and players on both sides because of this, which I think is pretty nice.
Just log in to Firemaw and you will see what I am talking about.