Shiiiiiiiit, I'm definitely seeing burn-in/ghosting on my MBP Retina.
I've had Preview open for about 25 minutes, not moving, importing videos in from my iPhone, and I clicked iTunes (which is set to open fullscreen), and when it went to that grey background that's behind full-screened apps, I could just barely see a small vertical line (the edge of where the white preview window was) still faded into the screen. I minimized it and when I next checked (about 2 minutes after minimizing it) I couldn't see it. Also just tried looking for it using where the edge of my Chrome window is, and I can see it too. Only when I'm really trying, though.
My serial number says the week of production for it was 24, and a lot of other Week 24's have had the same problem, apparently. I've seen a lot that are really really bad, and honestly, mine is barely noticeable.
For all I know, it could be normal for these types of panels. I have no clue, but fuck, fuck fuck fuck...What should I do? I have AppleCare, so I guess I could get a replacement, but I would imagine that's a pain in the ass, right? I leave for school on August 24th, which is really soon too, and I can't afford to be without a laptop....fuuuuuuuuck.