I bought my girlfriend a 12" in mid-February, and we have not seen any warping. The battery life on hers is rarely over two and a half hours though. Our local Apple reseller had their people look at it, and they ordered a new battery. Even with all of the hints and suggestions we have found on the web, the battery rarely gets above three hours of life. Unfortunate, since she travels around with it quite often and would love to have an extra hour or so of life before needing to plug it in, which tends to cause it to heat up on the left side.