Has anyone yet determined whether the SSD is replaceable? The ordering page implied that it wasn't, but I can't distinguish between "we don't plan to sell upgrades" and "it's physically impossible to swap".
iFixit says that Apple is using some sort of proprietary SSD that is attached to the logic board, so I think you are going to have a hard time upgrading.
Turns out that, for elaborate reasons, I have two machines that I'm going to be using, and one of them is expected to be here today, and one of them sometime in mid-December.
Guess which one I have a significantly more pressing need for. And they're not (quite) interchangeable. But if I could swap SSDs between them, that would be useful.