wow, i don't like that at all, thats a LOT of oil not to be seeing any smoke.
Since this is under warranty I would, as suggested make some calls... were it not under warranty i would be checking the plugs to see if it is burning the oil.. because if it isnt, it HAS to be going somewhere... I am surprised they are letting you drive that.. being two quarts low is not good. They are taking a chance on losing that engine. When i was doing warranty work, I'd have been looking for the problem and fixing it, before we had to do a warranty engine. I would worry that they are going to say you knew about the problem if the engine goes away and not warranty it.... I do not know your dealer or how good they are to you, this may not be the case at all, but i left a dealership after only 28 days of working there because they had this very attitude. Keep records names and times. I hope they take good care of you!