For what will amount to be a $10-$15 subscription, anyone will be able to rent a dedicated server and personally administrate who gets to play on it. One hopes that along with this subscription, they'll have a better interface for this kind of functionality, rather than having youngins try to memorized text commands. Mojang is targeting families with this venture and thankfully only one subscription will be required per server. Realms also seems like an easy in for those who really just don't want to deal with that server mess to begin with, or even credit cards: the company intends on releasing Point Of Sale Activation cards to supplement payment options as well. Oh, and Realms on their Pocket Edition? Or portals between these realms? Yep, those are coming.
Source: Gamesindustry International