I can tell you that I have both. Just picked up a MBA13 for my wife last week. Spent all week on it, playing. MBA is a beautiful machine fun to carry around, it is supper light, kinda like an iPad almost. Fast and responsive, and the screen isn't as bad as they say. I had no wifi issues and got almost 10 hours of use on battery. Speakers are get for a small devise, everything else is like any other apple product. Solid and tight.
rMBP people complain about the screen image retention, I don't have the problem. Retina is beautiful but all in all I think I would prefer longer battery life. Haswell will impact that.
Both do not have DVD Drives. rMBP has HDMI out, the AIR needs a TB Adapter, the rMBP is faster for most users it's not noticeable. Only in picture editing and thats a small part of my life.
All in all it comes down like to what has been stated tons of time before. the AIR is much more easy to lug around, the rMBP is gonna be heavier. I like the Air a lot and if you need a better screen, connect it to a TB Display. YMMV as with everything. 2 cents.