Basically there's a bug right now that keeps you in your dungeon queue even after you log off. You can log onto another character and log back to your character in queue.
While I haven't been able to fully test this, the time in queue still increases while you're offline. I'm unsure if your queue can pop while you're offline, but definitely useful not losing your position in queue if you need to switch between characters to check auctions and such.
EDIT : After being offline for quite some time my dungeon queue was gone upon relogging, I assume this is due to the queue popping while I was offline.