The title says it all. 

What do you guys think ?

Will nintendo make the move to a conventional x86 or ARM processors to help fight against the increasing development costs that each developers face ?

Or will they aim to achieve backwards compatibility again with the WII U? 

I have to give both the PS4 and X1 some credits as well as a round of applause for trying to lower development costs. Some of you are free to as well. 

It won't be long until they reveal their next successor ...

Yes. Nintendo can't sell 3rds games so they will rely on a unified architecture to have their 30+ year bscklog of gam available to dampen the droughts next gen. They wont recode it all onto another architecture.. They'll keep ppc and why not?

Unless streaming games (at a good latency) is a thing next gen, or the next system is radically different....

I can't see why not.

Iwata already said that the next console will 'absorb the architecture' of the Wii U. I personally think it will be digitally backwards compatible with everything (possibly even their handhelds). Not discs though.

That could mean anything though ... 

Why keep it when when switching to x86 or ARM would be alternatives to fighting against the rising development costs ? 

I guess. If theres one thing Nintendo does right it's backwards compatibility.

You forgot about the gamecube ... 

In doing so their pretty much not going to attempt to solve the development cost issue with that route. 

I personally think they will shift over to ARM, they're cheap, lower power and AMD is now an ARM licensee and is now producing/Designing ARM chips, so they can make a very powerful console-orientated ARM SoC.
It wouldn't be a stretch to assume that it could end up with 8-16 ARM cores combined with a Radeon GPU.

And considering that the successor won't arrive for many years... ARM cores should be faster than Jaguar, easily.

With that in mind, it does mean Backwards compatibility would be broken at a hardware level.

Is Wii U compatible with GC games? Off topic but I really don't know.