In every NX discussion I've read, there is a common debate: people arguing which system of theirs they need to replace first. The 3DS is reaching 5 years old, and it seems that Nintendo's output for the system is slowing down quicker than the WiiU's. But even now the 3DS sales are still healthier than WiiU's in both hardware and software (this year the 3DS sold around 7m units, while the WiiU sold around 3m). However, with the NX project closing in, it's very possible that Nintendo will replace both, if the NX is a fusion system.

Which system do you think will be replaced first? The 3DS or the WiiU? Or will they be replaced at the same time by the Fusion system?

Also, if you want to make predictions about which system will be replaced first or last, feel free to make them here.

3DS Pros to replaced last /WiiU cons to replaced first.

-The 3DS keeps selling better than the WiiU. Both hardware and software.

-The 3DS is still getting more 3rd party support than the U (not counting indies, they are coming to both devices).

-Nintendo might not want to ruin their biggest money font without any failsafe plan.

-Nintendo needs to recover the lost ground on the home console market as soon as possible by releasing a new HC devce.

3DS Cons to replaced first/WiiU pros to replaced last.

-The 3DS is dangerously underpowered, and it's missing a lot of 3rd parties because of that.

-The 3DS is an older system. The N3DS didn't help that much.

-The WiiU gets more 1st party support than the 3DS.

-Nintendo needs to preserve the handheld market's health by releasing a new HH device.

Prediction : The NX is Nintendo fused with Xbox (Microsoft). Much like the Nintendo PlayStation of old, this will be a joint effort. The handheld component will launch in 2017, and the home console will be the next home device from both Nintendo and Microsoft, called the fusion launching in 2020. Boom.

I fully expect both to be replaced by the end of this year ...

It should have been the 3DS. There was no hurry to replace the Wii U in my opinion. Yes, it's a failed console, but it could have sailed two more years with Nintendo first party titles bringing the cash for Nintendo. It could have reached 20 millions with extanded support and a longer life.

Nintendo can replace the 3DS when they want since they are basically alone on the market of dedicated handheld where Sony has given up.

Replacing the Wii U too soon mean releasing a mid generation console and that's much harder.

But every rumors we have and then the lack of announced Wii U titles point toward the Wii U being replaced first.

They'll probably both discontinue near the exact same time.

The Wii U might last a couple extra months at most after the 3DS officially discontinues.

It'll be a simultaneous release for their successors imo.

I wouldn't worry about the "mid generation console" idea. You could argue that the wii u was mid generational and that the NX is a late start to current gen (especially since the NX won't follow the "wii" brand name)

The 3DS is more like to get replaced. If the dev kits for the NX were actually released in October/November (at it's earliest, anything earlier than that and we would've gotten some proper leaks by now), and if the NX is a home console, we're not looking at a 2016 release. Even the Wii U's dev kits were released 1.5 years before its launch. And we all know the quality of its launch line-up (sloppy ports of old multiplat games and only 3 or 4 new games for a good while).

The 3DS is pretty succesful and that's why Nintendo needs to replace that system. It sounds counter-intuitive, but the sales of the 3DS are winding down, they cannot let their most succesful platform fade into nothingness. The 3DS had its time, they can do way better in terms of specs for a handheld. The Wii U on the other hand, it's still selling the same as it did two years ago. Third party support isn't magically coming back either, so there's no hurry with replacing that system. They almost have to start building their userbase from zero anyway.

edit: Also, the idea of launching a new home console in the year the PS4 will be in its prime.. They're going to set themselves up for another failure if that's what they're planning to do. 

The 3ds will be replaced first. The wii u released about a year after the 3ds, by then Nintendo had done a lot more work on the 3ds successor without having started on the Wii u successor. The only thing they will share (imo) is OS but I don't think the NX is a fusion concept. Basically a system similar to windows PC gaming/ Xbox one gaming (unified under windows 10 but not really the same)

I don't know, the PS4 is in full force now and a I don't think the market is ready for a new home console now. It seems risky to me.

Too bad Nintendo has given up on Wii U marketshare. If they had dropped the price they could have sold Wii Us for at least two more full years. But the situation is not easy as they had to return to profits.