Re: The Maginot Line
>but it probably voids the warranty
Only if MS actually install a custom ROM without Samsung's permission. From reading the two accounts (Mary Foley's & CokeRobot @ Reddit), I suspect this is either a simple instore pre-install of selected app's whilst the customer is waiting, or Samsung is permitting MS Stores to download a custom firmware update that consists of the MS apps and removes various standard third-party app's.
If MS really are installing a custom ROM we can expect people to be very interested as it may provide an alternative and potentially simpler way of rooting Android devices...