It depends on what you want.
If you want a laptop that can go all day and do basic things, then get the MBA.
If you want a laptop that has some 'juice' but don't need a lot, then get the rMBP13.
If you want a laptop that has plenty of 'juice', then get the rMBP15.
Personally I think that if you want both, do:
rMBP13 - (weak mobility, non-future proof juice)
OR
(new)MBA + MP/MBP/iMac - strong mobility, strong juice
It just depends on if you want juice or not, and if you want one machine or not.
I think that Haswell made the MBA have much greater battery life. I think that for the rMBP13, Haswell will increase the power by >20 percent instead (it all depends on what Apple is interested in, they rightly focused on battery for Air, but will want power for rMBP). Since the MBP15 has discrete GPU, I expect Haswell to only increase power by <10 percent or less.
Jon
Somewhat better upgradability.
One thing to also keep note of is the 5000 vs 4000 intel graphics. The 5000 is a considerable upgrade of the 4000 and is pushing a much smaller resolution than the rMBP. That being said if gaming or video editing are of concern you're better off going with an i7 MBA. The stress of the rMBP resolution coupled with the weak GPU aren't the best combo.
What are the advantages of getting a rMBP over MBA 2012/2013 besides the Retina display...
Thanks for the reply, I currently own a 2012 Air my uses are pretty casual nothing too heavy , I might not need the new MBA After all, I might wait and see how Mavericks operates on this MBA
rMBP13 - (weak mobility, non-future proof juice)
Mavericks will run fine on a 2012 MBA. You do not need to replace it.I currently own a 2012 Air my uses are pretty casual nothing too heavy