Alright, so I just got back from the Genius Bar a little over an hour ago and here's what happened:
First, I made sure to switch my wallpaper to the darkest gray color of the 3 grays. I went to a website posted on this thread somewhere that is very similar to Apple's test (more on that in a bit) that basically shows a white and black checkerboard pattern that shows said pattern for 5 minutes before switching to a dark gray/light gray background. Additionally, I showed the Genius my background just to confirm that it wasn't just the web page faking it; he agreed that he saw it.
So, that's when he went to a page on the Apple Store's intranet on my MacBook Pro which showed the exact same pattern for 3 minutes, but then showed a black background (where you can't see anything) instead of the dark gray color (where you can see the ghosted image), as mentioned in this thread. After examining the black-colored screen for a timed 1 minute, he said that my MacBook Pro with Retention...I mean...Retina Display passed the 1st party test after it failed the 3rd party test, he went to speak with the manager (who I know, by the way).
Fast forward a couple of minutes; he came back and said that he'll make a one-time exception and swap out the display. I asked if there was a way that I could get a Samsung display (since they had replacement displays in-store) and he said, and I quote, "I'm not gonna go there!". He further told me that everything should be done within 3-5 days. So, I acknowledged him and parted ways.
But I didn't part ways with the Apple Store yet, as I went to see the manager and talk with him about the issue. He said that he allowed it this time because I noticed it and that it bugged me. I asked him that, if the replacement display were to have the same issue, I could get a replacement screen again. He replied, just as the Genius and others who were brave enough to play the "perfect LG/Samsung display lottery" said, "It's within spec.". When asked about why Apple uses a black-colored background instead of a dark gray, he simply stated "I don't know.", although he did mention that he has heard of the IR problem and ways to check your screen for the manufacturer, etc. He also added that his screen didn't have the problem.
I left, went to my car, and prayed about it and thanked The Lord that I'll get a "perfect" display. No joke.
So, to wrap things up, unless your screen is that bad to where you'll notice ghosting in everything you do, I wouldn't bother going through the hassle. Also, take this as a warning to those of you who are considering getting a MacBook Pro with Retention, sorry, I mean Retina display. You now know what you might have to deal with. This should also go as a lesson to those who are as OCD as I used to be: don't be so anal and try to get the "perfect" product because, like the lottery, you're going to lose. Plus, the Apple Store that you get obsessive compulsive with will record you "long history", much like mine did when I got so stupid over a small dead pixel with multiple iPhone 3Gs back in 2009.
Again, I will let you know what the results are when I get my "perfect" MacBook Pro back. Until then, I will follow this thread and see what others have to say. Sayonara, for now.