We're honestly not 100% sure if this isn't an elaborate fake, but we'll leave it to you to make your own minds up. This Reddit thread makes a convincing argument for the existence of a Mario Kart 8 Deluxe bundle for the Nintendo Switch. The theory is that this will be announced later today in the Nintendo Direct for ARMS and Splatoon 2, which makes sense.
The leak originated at the Russian Nintendo store, however you can only view that site from within Russia. So you'd need to use a proxy to view it.
The box art is slightly different between the grey and neon version and something doesn't look quite right about them. But then again, what do we know about marketing in the Russian territory?
Let us know if you think this is legit with a comment below. If you haven't bought a Nintendo Switch yet, would you welcome such a bundle?