I started following the threads about this issue down in the rMBP subforum, before I ordered my 2014 rMBP in January. At the time there was not a single 2014 owner reporting this problem, so I crossed my fingers that Apple had silently solved the issue and ordered my rMBP.
I have been babying my rMBP's screen to a bizarre extent, I even ordered a fresh lens brush (like you have it for camera lenses), so that I could gently dust off any particles instead of potentially scratching the screen while wiping them off. I have also only ever used breath (was even too scared to get it truly wet - also we have incredibly hard water here in London, so who knows what that would do) and the black microfibre cloth to wipe it. I have yet to take my rMBP out of the house for the first time, so it has never experienced the pressure of traveling in a padded sleeve in my work bag. (Which I expected it to handle as well as its much cheaper predecessor MBA did.)
Yet around the camera the coating already wears off. Just great... exactly what I imagined when paying that much money.

I've made great experiences with Apple's customer care and the smudge is not bad yet, so I'm not worried at all, only annoyed that a problem that has been existing for several rMBP generations, has not yet been fixed. Come on Apple! Kindly redesign the rubber band or hinge thickness or whatever your engineers deem to cause this problem!