When I bought mine a month ago, the dealer knocked $1000 off straight away, then wouldn't budge after that (until I had a delayed order and they gave another $250 off as a goodwill gesture).
I think it depends on the dealership. I hear some aren't giving any discounts now as stock is in short supply. My local dealer is adding $3000 to the MSRP price of BRZs... and getting it. Bottom line - if you want the car badly enough, don't walk away from it for the sake of a few hundred dollars.