I want a pause button in my MMORPGs. Yeah, I know that sounds crazy. Certainly, we can't pause the whole server. But games are different these days! Many MMOs are highly instanced. If I'm in a solo instance, why shouldn't I be able to pause the game if emergency strikes? If I'm gone for a short period, its not adding undue load on the servers. If I'm gone long enough, the servers could swap the server instance out to disk until I return. Chat channels and other shared world features would (of course) still continue normally, only the zone server for the instanced mission needs to pause.
While soloing an instance in Guild Wars or EverQuest II, I have to run and find some nice safe corner to stand in should I need to go AFK for a little while. Unfortunately, real life emergencies don't always strike neatly between encounters.
Many people with time constraints are attracted to MMORPGs for a number of reasons, even if we do find ourselves needing to solo much of the time. We like it because, unlike single player games like Oblivion or Morrowind, they allow us to group with others when we do have time to do so. We like MMORPGs because the content is constantly updated (most single player RPGs get a few patches and maybe an expansion pack and that's it.) Interacting with other players, even indirectly, through the auction house, also adds a lot to the game play, especially in MMORPGs with more player-driven market economies.
Obviously, this kind of feature wouldn't work in parts of the game world that are shared by multiple users, but I don't see the drawback to allowing this type of feature when players are in a part of the world where they can't adversely impact anyone else's play.