Are we sure about the existing RAM issues (as opposed to future-proofing)? Am considering the rMBP, but the only way I could pull it off would be to use work given Amazon GCs, thus eliminating the possibility of RAM customization through Apple (and the upper model is too expensive). Course there are a ton of pixels, but 8GB seems like a bunch of RAM for non-video editing/CAD operations. Hard for me to believe Apple would handicap their flagship laptop from the start.
Edit: Now that I look at the upper model its base is 8GB too.