I saw this on NeoGAF and though I'd post it here as well to see what people think.

http://blogs.barrons.com/techtraderdaily/2014/06/10/amds-papermaster-moshkelani-talk-wearables-infrastructure-server-chips/

The quotes that are making people think this, "Another area of interest for semi-custom is handheld gaming, believe it or not. “Everyone thinks it is dead, but the [Nintendo] 3DS is still selling.” And this, "“Has to be at least $100 million annual revenue for us to go for it,” says Moshkelani. That’s a minimum, he explains, not a target."

A couple of points here.

1. How powerful could it be using AMD? Could they get it to around Wii U level?

2. What about backwards compatibility? It was my personal understanding that both the next handheld and console would be backwards compatible with the Wii U since they are using the Wii U as a starting point for their unified architecture.

My only issue with having the next potential handheld also be compatible with wii u discs is that the reader would not let it be very portable anymore... Maybe a separate peripheral that came with the handheld?

What exactly is AMD?

Well if it is indeed the case that it will ne able to play wii u games it would be only digital. Like yoou said, it would be too big.

AMD is a  semiconductor company they make GPUS and CPUs

1. If it has WiiU's raw power it would need to be around the same level as a Surface Pro machine, but that thing needs a fan to run and the surface can get hot. I think Nintendo would want a cold/fanless machine. It would need to have 2016/2017's tech to work, but I don't think Nintendo will use newer tech.

2. If they still PowerPC maybe, but they would need to fit that in a handheld. Unless they find something else.

1. I think mobile is at least approaching Wii U levels especially with Nvidia Tegra K1.

2. They said something about the next platforms "absorbing the wii u architecture"

 Buy on Wiiu and play on NIntendo WiiDSu

That's why it's still going to run hot. Tegra K1 TDP is supposedly 11W at max load, that's hot. It was at 28nm node. Let's assume by 2016-17, when 16nm finFET is ready, power consumption is reduced by ~50%, that would mean about 5.5W. 11W would be no problem for a actively cooled tab like Surface and 5W is not a problem for a iPad/SG tab size devices, but will still be a problem for handhelds like Vita/3DS.

Yea Tegra K1 would be too expensive anyways, but even shrinking down the current wii u soc would be something since it's 45 nm. I was reading an AMD presentation and it said that shrinking from 40 to 28 nm reduces power consumption to a third of what it previously was IIRC. Given that and a slight downclock you could get it pretty low I think.