Okay, so I have a rMBP 13 inch base model, and I'm regretting not getting the RAM upgrade, or even the processor upgrade. It's perfectly fine for what I need to do now, but I'm just worried for when it starts to pack on some mileage and 4 GB RAM isn't quite enough (Which I'm betting will be soon). So, would it be possible later down the road to swap a motherboard with one that has more RAM/better processor? (I think there's a 2.9 GHz dual-core i7?) Is it even a possibility? I'm pretty sure you can remove the flash storage so losing files wouldn't be problem. At least that's what I think.