You're in luck because NX apparently has detachable controllers you will inevitably lose when they aren't overcomplicating the simplicity of a self-contained portable gaming system.
In all seriousness, I'm in favor of Nintendo starting over completely which includes no legacy controller support. The Wii U Pro Controller is overall my favorite controller ever and I'm admittedly cheap, but I think it's better for Nintendo. One main controller. The GamePad variant must have the same layout/feel (particularly the shoulder buttons). Wii Remotes must be remodeled, rebranded, and downplayed as "classic" controllers. Oh, the delicious irony of labeling it "classic" and pushing it to the side.
A handheld that plays games on par or better than Nintendo's current console which can still be displayed on a TV with a simple HDMI cable is very exciting to me. That's Nintendo bringing things back to basics. Nintendo doesn't need controller gimmicks, or if it insists, the controller doesn't have to be the main selling point. Nintendo proved that with DS/3DS. Its greatest gimmick was always its own first party output. Now, sell the hardware cheap and that's a good start. It isn't a great one because there's still much work to be done: the operating system has to load instantaneously, the marketing has to make sense (and be existent), Nintendo Network has to matter, myNintendo has to be deeply integrated, the netcode has to sing, Virtual Console can't be a colossal clusterfuck like it is now etc.
Going mobile as a means of marketing is a great idea. Nintendo is giving Apple and Google 30% of its mobile sales to remind people Nintendo exists. All the people who already play Mario aren't going to stop just because they can get an endless runner starring Mario. It's for the people who said, "What's a Wii U?"
Apps like Netflix and Amazon are nice (and Nintendo really needs those sports apps), but I rather like the idea of getting to the title screen of a game within 10 seconds of booting up the system. If Nintendo made that an option, that's the biggest message it could send. That's a perfect way to push the idea that there's no play like NX.