Well, here's my story:
Both my girlfriend and I have iPhones. I noticed my screen was a bit dark and showed negative images in the black areas (as everyone else is noticing here). So I compared it to my girlfriend's and WOW, HUGE difference. So since I was still under my 14 day return deadline, I went to my local Apple Store (Garden City, NY). I had to show the issue to 3 people before I could get an exchange... it was apparent they didn't want to acknowledge there was an issue with my iPhone.
So when they brought out the replacement one, it had the SAME problem. When I tried to explain that this was unacceptable, they told me that there are two display manufacturers and it is luck which one you get--but both are within Apple's specs. After I pushed the issue, they opened another one and I got lucky with a good version.
I asked them, "Honestly, I know you have to obey certain protocols, but you can see why I have a problem with this, right?" The manager just gave me an attitude saying that until Apple officially acknowledges there is an issue, there is nothing wrong with this phone. I explained how this was just like the iPod Touch problems which Apple DID acknowledge and his reply was simply that it is an entirely different issue and it has nothing in common with iPod Touch. This guy got really adamant and was extremely confrontational, despite my trying to calmly reason with him. He basically tried to make me feel privileged to get a working product and not have to pay TWO restocking fees.
I have to say, time and time again I have the WORST experiences with the employees at Apple Stores. I have been using Apple products exclusively for 15 years, and I know my way around the hardware/software very well. Yet, more times than not, I am reduced to a simple-minded, ignorant and lowly consumer in their eyes and they have no reservations about letting me know it.
At the end of the day, I am happy they finally did the right thing, but to act like they are some kind of authority figure (and not a common sales person that they are), really has been leaving a bad taste in my mouth since the store's inception.
Bottom line is, there IS an issue with the iPhones (ane very MUCH like the iPod Touch issue). Be calm, state your case, and most of all be firm and hopefully you can get an iPhone that is working they way it SHOULD.