I'm not one for thinking Sony will drop the price of the PS4 but if they DO, then dropping it by $100 during the Halo/Tombraider window would probably wipe out any advantages MS have. Then when the price eventually goes back up again, raise it by $50. Release the slim when Uncharted: A Thief's End launches and lower it permanently by $50.
That's what I would do IF a price cut is on the cards.
The PS5 Exists.