Obviously, there’s no detachable Joy-Con in this design, and it wouldn’t come with a standard dock either (although, the designer claims it can still be used with the dock–except I don’t actually believe his design would fit in a standard dock without the analog sticks getting in the way), but it’s got most of the basics covered.
You can read more about the idea here.
Oh, and it kinda reminds me of this. . . . 😉