Fair enough. But part of it will be taken from the VESA standards: from what I've read, the display port interface will be updated to allow dynamic refresh rates. AMD will most likely only provide driver support on their cards. Nvidia might be able to do the same, unless there are architectural differences between the GPUs that will prevent them from taking advantage of it. Of course, they might not want to do that, considering they already have a working alternative.
That said, that monitor does look sweet, G-Sync or not.