Should I buy then replace a rMBP?

Hey guys, am starting college this fall and I really need a new laptop. I currently have a shitty dell vostro and was planning on getting a 15" rMBP. School starts August 26th and I cant fathom using the dell for school work and other stuff like adobe creative suite. But I dont want to buy the current rMBP then a few months down the road they release new haswell rMBPs with improved battery life. I have considered the new MBA but the screen is a major turn off. Is it possible for me maybe to buy the current ones(2013 MBA or 15" rMBP) then send it back to apple(with a few bucks) for the haswell rMBP ? Any advice is welcome. Thanks