For me this sounds like the best machine short of a Mac Pro. (iMac not interesting for me due to its glossy screen and the lack of expandability of a laptop without having the mobility of the laptop)
It has no optical drive to burn CD's to give clients. You really think a photographer will keep a lot of clients if they tell them they have to go online and download their pictures? Or do you think in 2012 people are content with a handful of prints? As far as editing, a typical shoot for me is 500 pictures, 12 meg raw files, so about 6 gig, plus edits, giant PSD files, and my finished jpegs, I'm usually around 10 gig per shoot. A 768gig SSD is way too expensive to be storing pictures and still pretty tiny. I'd rather have the thing 1/4" thicker than have to carry extra devices and dongles. you sure give up a lot for that 1/4". And the MBP is already really thin.
The screen is small and the "retina" feature is useless for photography. I want a good viewing angle so the colors don't screw up as I move my head, and something that I can calibrate so prints match what I see on screen. More pixels might make a picture look better on screen but they don't help at all as far as processing an picture into a final product.
Things like the soldered ram, glued battery and non-standard drive interface make the rMBP a DOA product for anyone who's not an apple nut.
Also, I think a retina MBP can render an iPad obsolete as the 15" screen should be great for demos to clients (and the screen stands up on its own, no need for a holder, and the display has, so I heard, a good viewing angle to be looked at by more than one person).
Really? What kind of photography do you do?
Among other uses, I have an album of about 50 of my favorite pictures I've taken on my iPad and there are times when in the middle of a shoot I'm having trouble getting the model to understand what I want. I'll pick up the iPad, choose an image, and show it to the model to get the idea across. Try doing that with a 15" laptop. While you're holding a camera, there's nothing to rest the laptop on, the model is under the lights, and you've got a make-up artist/sylist standing over your shoulder. It's also good to have a free hand while doing that to point at details
I also like the iPad to show clients finished pictures, it's so easy to load their album and hand it to them to flick through at their own rate. Sitting around a computer advancing the pics for them makes everyone feel less comfortable. No need for a holder when you hand them the iPad.