Generally, submissions go to Programming, who then decide what's going to go on the schedule and who's going to be on the panels (assuming it's not a solo presentation or the submitter has their own preference list). At least that's how con programming works in this neck of the woods; I assume different cons do different things etc.
Mr. Fnord on FFN and Mal3 on AO3 • Conceptual Neighborhood - yet another damned sci-fi blog • The Westerosi (ASoIaF) • The Westerosi II: Subprime Directives: Extradimensional horrors threaten the Seven Kingdoms, and Captain Hasegawa of the Starfleet Rangers has to stop them. If she accidentally conquers Westeros in the process... oops? • Fenspace (shared world)
"It is your job to personify the tyranny of the majority. You must brutally, ruthlessly oppress and persecute the fuck out of the poor misunderstood disruptive creep minority so that the privileged nerd funhaver status quo can be maintained. It's a thankless job, but somebody's got to do it. Fun Über Alles, all hail the Fun Tyrant, without him our campaign is lost." --SA user Angry Diplomat, on the GM's role.
"It is your job to personify the tyranny of the majority. You must brutally, ruthlessly oppress and persecute the fuck out of the poor misunderstood disruptive creep minority so that the privileged nerd funhaver status quo can be maintained. It's a thankless job, but somebody's got to do it. Fun Über Alles, all hail the Fun Tyrant, without him our campaign is lost." --SA user Angry Diplomat, on the GM's role.