Another thing to note, if you already have a PS3/Vita with PS+ then you should be able to use the Playstation Store website to purchase PS4 PS+ freebies as they are released. This way you do not miss out on anything released to PS+ for PS4 before you actually own the console.
Of course this is assuming it lets you see PS4 games on your account without already having one registered, but I would expect it would.