So the NX is a handheld and the dock likely does not provide extra performance so it is not that much more powerful than the WiiU? Resolution of games is prob. 720p max.

So will games like the new NX-Mario be ported to the WiiU?

Are there technical limitations of business reasons against it?

No too much work.

Wii U = old impossible to code for CPU (IBM arch) + old AMD GPU arch.

Nintendo Switch = Arm cpu arch + Nvidia gpu arch.

Maybe some older Wii U games will be ported to the NX, if they still have the source files, and they where made in programs that can also easily run on the NX.

But the other way around? I seriously doubt it. Dont expect any NX games to show up on the Wii U.

Thats a rumor.

Nintendo themselves have actually said it doesnt, give any extra performance.

We have a thread about it called "Nintendo: Switch dock only for charging and TV-out".

No, they won't

There is only one game left for the Wii U and Nintendo is done with that system :/

Waste money for a dead system?

Of course no.

Would be nice but that would kind of stop me from upgrading

That would be a waste of time and money. The NSwitch is a new beginning for Nintendo. They're not going to go back, that wouldn't bear much if any profit at all.

If anything, Wii U games will be ported to the Switch. No way are Switch games getting downgraded for the Wii U

The WiiU is dead, it is now in the hall of fame of the cool consoles that did not sold well, among noble names like the Dreamcast and Sega Saturn.