Got my black 32GB wifi iPad 2 on Thursday. On Friday, I went to watch a movie on it and noticed light bleeding from the bottom of the screen and a stuck pixel. On light colors (yellow, light purple, etc) it was showing up as an aqua or turquoise color. On reds, it was black. On darker colors it was red.
Called Apple that evening (Friday) at about 7:15pm and was able to set up a Genius Bar appt for 8:40pm. Brought it in and showed him the stuck pixel, didn't even mention the light bleed. He went in back and came out about 5 minutes later with a new sealed black 32GB wifi iPad 2. He went to hand it to me and I told him that my power adapter wasn't in the box, so he could pull the one out of that box and put it in the old box. He told me it didn't matter and not to worry about it.
No pixel problems on this one, and haven't noticed any light bleeds either (but I haven't tried to watch a movie on it yet).
So far, of all the companies I've dealt with, Apple has the best customer service. They had also replaced my iPhone 3G when I was having the common freezing while asleep problem with one of the 3.x OS versions (I forget which version) even though it was over a year old and out of warranty. Apparently when I called Apple C/S, I was one of the early people to do so, and they wanted to send it back to engineering to see what was causing the freezing with the software. They took a brand new iPhone 3G out of a box and gave it to me, not a refurb. Apparently Apple C/S had told them to do that.