fwiw http://www.anandtech.com/show/10710/amd-announces-embedded-radeon-e9260-e9550 

Good. Someone needs to put the pressure on Nvidia. They had the desktop space free for too long. Maybe now AMD can also compete on mobile, but ill believe it when i see it.

Wii U has 352 GFLOPS, so half a TFLOP (500 GFLOPS) makes it roughly 45% more powerfull than Wii U... not very impressive unless it's a handheld, which is nice enought power in that case...

How is it too late?  Not unless they've already started production and have enough inventory they don't want to lose.
MS upclocked Xbone's spec at the very last minute, if you recall.  Doesn't sound like any architecture change at all, in fact.
Really, if you have a great insight why something is impossible, it'd be good to share that upfront rather than play coy.

Yeah, of course 50% seems on the high end, but the FinFET 14nm is very new and very innovative, with 3d structures
one could say there is more "surface" of the process that would be able to be tweaked and thus have larger scope for gains.
The idea that a 9month+ delay would enable Nintendo to base their spec around better process tech is entirely unsurprising.
And to be clear, Sony should be able to use the same improvements, but if the spec re: clockrate is already set, they won't benefit there.
(just in terms of lower thermal profile, allowing less intensive cooling, smaller case for slim, lower power needs re: power supply, etc)

I'm surprised nobody has mentioned:  
If Nintendo is in position to benefit from this, then certainly MS would be able to as well with Scorpion.
Although I guess that's because they are already rumored to be using beefier GPU, CPU, and so only result is impact on power/cooling of that.
This does give basis for them to have that performance spec without going over-board on noisy fans, large case, etc.

I believe it was shown that Wii U actual power is around 175, which would put the hybrid way below Xbox One power.

I don't understand what you meant here... :/

I don't know how reliable this is:

http://kyokojap.myweb.hinet.net/gpu_gflops/

But every site I read says 352 GFLOPS...

There was already this big argument about it, but Neogaf verified it at 175 or so. Who knows if its true though.

This is definitly good news for NX and a future PS4 Phone/Handheld. If Pro is not built on this, then it won't be lonbefore the 7100 series Pros hit the market with small PSUs and lower operating noise. All in all, this is great for Son, Microsoft, and Nintendo, and the future of home and mobile computing on consoles.

So AMD has the products cited in the wccftech article, so what?

Looking at the anandtech article you linked, you can see that those new products replace another two, produced in 28nm and with an older and less efficient architecture that don't consume that much more power and, in fact, use a lot less power than their desktop counterparts.

For example, taken from that article, the E8950 that is replaced by the newer E9550 is based on the Tonga architecture, features 2048 shaders and is rated at 95W. The desktop version would be the R9 380X that is also based on Tonga and has 2048 shaders, and guess what, it's rated at 190W. And that's despite being a 4GB card compared to the 8GB of the embbeded product!

Summary: using embbeded products to extrapolate the performance or power consumption of the desktop versions doesn't work.

NX wasn't delayed! March 2017 was NX first official release date!