I just got some good news from my GameStop, for a change..
He said they'll definitely have it on Tuesday. Either they'll wait for the shipment from UPS and have it around noon, or they'll send someone to Houston to pick up the shipment and have it ready when they open their doors. Which is definitely better than they usually do, since they have a habit of getting new games a day late. I wasn't expecting it until Wednesday.
He did recommend pre-ordering, though (which I've already done). He said "That way, you'll actually be able to get it", which tells me that they have a large number of pre-orders, and probably not that many "spare" copies to actually put on the shelf for walk-in customers.