Nothing too fancy going on here. "Exodus" comes from the Greek word meaning "to come out." Makes sense, right? After all, if the Israelites do anything in this story, it's get the heck out of Egypt.
But wait a second. The Hebrew title actually translates to "Names." Why would the writers have called the book Names? Maybe because it's the first time in the Hebrew Bible that God reveals his name (YHWH) to the Israelites? Any other ideas?