I also took mine to Apple, and wouldn't swap it out. They just kept saying its normal. All they did was reset my iPad, saying it was a software related problem. Not hardware. So I'm here now waiting for my backup to restore, and not expecting this is the fix... Told him if its still doing it, that i could then get a replacment. Software really? I'm going to keep posted.
Oh to the guy who gives us a lecture about Thermal Runaway... Dude, this is tablet meant to be held, without uncomfort. Yes, the iPad has been beefed up with better graphics, screen, ect... That does not mean is ok to be hot! Customers don't need a lecture about how thinks work. We just simply want a device that works correctly, and comfortably, which the first two did. Period!