I keep asking myself this: given all the static Apple is getting from various reviews (including Anandtech, Verge, ...) about the lack of an option to upgrade the base rMBP to 512 GB SSD, and given that iFixit shows that these can be easily replaced in principle, could it be that Apple will offer an upgrade of these things to their customers who got the 256 GB option early on? It really is pretty pathetic that they don't offer this unless you pay $600 more for the model with 10% faster processors (which most people don't need). I'd bet that if you did a survey, ten times more of those getting the base model would be willing to shell out $300 for the SSD upgrade than would be willing to pay the same amount to the faster processors. I would, and the only thing holding my three friends in the market for a new Macbook back from getting the Retina is precisely the lack of said option. WTH Apple...this is ridiculous.