I agree with the portable console approach if that's what Nintendo takes.
Even with 3DS ....
3DS = 20 million sold in Japan
Wii + Wii U + GameCube combined = approximately 17 million
The support a Nintendo machine that was actually a capable console style hardware but had the userbase of their portable side would result in a platform with a ton of Japanese support IMO.
3DS/DS did not get the support they should have because they were portable-only devices that can't run the higher end games, if Nintendo can bridge that gap some they would get a lot more Japanese support.