Yeah Applecare isn't going to call this a defect. It was like pulling teeth to get them to admit the horizontal lines issues in my last gen 15" powerbook was a problem. Apple just does not like to admit there is a problem with something. I suppose in this case the neven backligting for most people is very minor so I can see where they are coming from.
iBorg, you say you have a perfect screen. Do you have the matte or glossy?
Glossy!
If your lighting is truly, noticeably uneven, I wouldn't accept that as "normal." BTW,
no notebook manufacturers "like to admit there is a problem with something" - it's the nature of the product and what they consider "within tolerances." And unlike stuck/dead pixels, which can be counted, the unevenness of lighting is somewhat subjective, so harder to get action taken to repair/replace.
As said here many times before, be firm, yet civil and respectful, and you'll get the best results. If dealing with a store salesperson, ask to speak with the manager. If dealing with apple.com, if you're getting nowhere with a tech support person, call back a few minutes later, and you'll get a different person, who may be more sympathetic/helpful. I've had 180 degree different opinions, a few minutes apart, with support techs in the past (e.g. first one told me that a failing battery was not covered under AppleCare, and the next one shipped me a new battery overnight express, free of charge! Last year, right before my TiBook's 3 year warranty was about to expire!)
Good luck in getting this fixed - you should be able to get satisfaction in this!
iBorg