Suppose that Apple released two versions of a Haswell MBA, one with retina display (rMBA) and one without. Suppose that both are identical in regards to weight, size, and dimension. However the rMBA will have only 6 hrs of battery life (due to the removal of some of the battery cells in order to keep the weight identical to a non-retina MBA, and also because the retina display consumes more power) whereas the non-retina MBA will have 12 hrs. Also to make it a little more realistic, the rMBA will cost an additional $300 more. Now which would you rather buy? I have a feeling that this hypothetical question may be more realistic than it appears. Suppose that Apple analyst Ming-Chi Kuo's prediction that the Haswell rMBP will be slimmer than its current form turns out to be true, then this new slimmer rMBP will roughly be like a retina MBA but with less battery life than the current MBA.