Well, here's another data point for you all...
I purchased my black 16GB wi-fi at a Walmart on launch day (last Friday). The first thing I noticed out of the box was the leaking near the home screen button and the bottom right corner (assuming the home screen is the bottom). There was a little bit on the top right corner too but not as noticeable as the bottom.
I was approaching the 1/2 way mark with the Walmart return policy (14 days), so I was getting a little concerned and wanted to see what my options were. I booked a same day Genius Bar appointment at my local Apple Store. Brought the thing in, showed him the leaks on an iPhone sized app (with the black borders). He said, "yep, I can see it there" almost immediately and said that he'd go back and look to see if they had any in the reserve stock (meant for this kind of issue exactly, I presume...well, and DOAs and whatnot). Anyway, after a little while, he came back with a new replacement and after a little bit of paperwork, we swapped iPads.
Not all that confident that this new iPad would be the answer, I asked him if I could bring this new one back if it started showing signs of leakage too (do any NOT have leakage out there?). He said I could bring it back under warranty anytime in the next year (and it didn't seem to matter that I got mine at Walmart). I feel MUCH more comfortable with this 1-year window through Apple rather than the 8-day (and dropping) window with Walmart.
Unfortunately...the new iPad has equal or slightly worse leakage...(the long exposure seems to exaggerate the leakage a little bit, but it is DEFINITELY there)...
Aperture: f/3.5
Exposure time: 1
Lens F-Number: f/3.5
ISO: 400
At this point, I think I'm just going to hang onto this one for a few weeks and/or months to see if the issue will get any better...and if not, I guess I'll have to bring it back again...but only once supply has stabilized. For me, there's no sense in going back all the time and cutting into their iPad reserves just to gamble on the chance that the next screen is going to be better. I just feel a lot better now that I can work with Apple and not Walmart on this issue.