You can plug it into a display, and plug in a mouse + keyboard.

I'd be inclined to buy one of these for gaming and an ultra light laptop for laptop stuff when the time comes, versus getting a gaming laptop or desktop.

But with it being designed to run AAA games on 1280x800 at 30fps, how good is it going to be on my 4k 60fps display?

That is my question also and presumably the answer is "not very good" but we'll have to wait and see as I can't find any info on this. Surely they'll have to rate the experience on a per-game basis when in 4k docked mode else (a small number of) people won't be happy.

Not to mention that 60fps is considered nearly unplayable for competitive FPS players.

Competitive FPS players would never pick this unit or similar up with an intent to play competitively on it.

Competitive FPS playing is kinda like NASCAR. The hardware and configuration of hardware is critical if you actually want to win.

Well I guess I don't necessarily mean professional competitive players, just people who play a versus game and take it seriously. If you could plug it in and get 120FPS, I could see some of these people consider getting one, especially if it overlaps with their interest in non-competitive games.

Something similar to the Switch.

Good enough for 85% of gamers, hilarious-looking and infuriating to any serious hardcore gamers.