I also have this yellow tint on the top left corner of the display. I am on day 3 now and I wake up to it gone, but after some use it slowly fades back in, then I leave it a while and it fades away to be just barely visible (which will always bug me if it remains like this), I am hoping a few days like this and it will work its way dry/cure.
I had an appointment with the Apple Store genius people today but I've canceled it, as I doubt they will have any replacements in the afternoon of the first shopping saturday after its release. I'll give it a week and if its still there ill set the wheels in motion again in getting it replaced, as you pay good money for these things and it shouldn't be a dud like some of these are.
It sucks a bit being in limbo and having to prevent really enjoying it (as in loading all the things on and customising it the way I want) when I know it may have to be returned pretty soon.
ho-hum, lets see how things turn out this coming week.