Help me decide 13" MBA or rMBP

I'm going to buy yself a new macbook but I can't decide which one to get. I am deciding between the 13" MBA and the 13" rMBP (the new ones that will come out in 2014).

I don't need the power because I have a 2012 27" iMac at home. I'm going to use the laptop for college, maybe some light photo editing when taking photos on vacation and some Steam Counter Strike when bored. I like the screen of the rMBP but 3 hours less battery life is a dealbreaker. Right now I have a 2012 15" MBP and the 1440x900 resolution woud be the same on a smaller 13" screen. It would be an upgreade.

And when are the new ones coming out? The Airs have been released in june at WWDC for 3 years now. The retinas have been relesed in october the last year. The problem is I can get a 15% discount from my friends university but only till september at the latest. So if the retinas don't come out before then it's already decided.

Thanks for any suggetions :)