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