Just a note to ANYONE flying pretty much ANYWHERE right now - you know that bad weather we've been having on the East Coast lately (continuing today)? Well, airlines are INUNDATED with calls from immediately-affected passengers.
Now is NOT a good time to call regarding future flights or information.
Besides, if you were to get through to Southwest, the reservationists would tell you something to the effect of, "We'll know when you know". SW doesn't reveal the information on schedule extensions to their employees. Sure, they now post the (subject to change) date on their website - but the employees don't have any inside/advance information.