Seeing as how the New 3DS seems to have gotten off to a decent launch, but it was primarily marketed towards adults it seems. The TV marketing was on Better Call Saul/Walking Dead, the commercials for the first time in a long time actually mention processing power, and they pushed games like Monster Hunter and Majora's Mask, which Iwata has said has a mostly adult fanbase (as in the kids who played MM back in the day are now adults). 

With the competetive market being what it is today -- lots of cheap tablets and hand-me-down smartphones for kids with $1/free games, I think maybe Nintendo ought to look at going upmarket (high end) for their next handheld at least initially. Have a very high-end chipset. Don't cheap out on RAM. 

I'd say try to keep the price between $200-$250 ... $229.99 maybe is a sweet spot where the extra $30 lets you buy a lot more in terms of tech components but it's fairly easy to knock $30 off the price 8-12 months down the line (so long as you don't invest in some kind of crazy gimmick). Cool looking design, don't make it look like a toy. 

Front load the system with games more enthusiast gamers would want. Mario Galaxy 3, Hyrule Warriors 2, Bayonetta 3, Monster Hunter 5, cut a deal with a Western developer to have a really good FPS. Bury the hatchet with EA, get FIFA, Madden, and Star Wars. Maybe even bring back Nintendo Sports (NBA Courtside starring LeBron James or Kevin Durant?). New Ninja Gaiden from Itagaki as exclusive, Xenoblade X port, etc. 

Keep the New 3DS around as the budget/kids option for a few more years. $129.99 for the standard N3DS, $169.99 for the N3DS XL. Make more DS and GBA back catalog games available too for N3DS, that should provide hundreds of additional titles to play. 

Yes.

That is what Sony did with Vita and it ended up poorly for them

No, because Vita

Vita doesn't have Nintendo games. There are more Pokémon fans out there than Vita owners and that's just one franchise.

I think Nintendo should target adults, teens and children with different ads on different tv channels.

My gut reaction is "NO!!!!!!," but after reading your post it seems clear enough that you mean that they should have a more balanced focus on adults, kids, and teens. To that, I say definitely. But kids are why handhelds live, and losing them is why they die. Never lose sight of that.

Yes, definitely.

But keep the "everyone/kids" tier games like Pokemon or Yoshi.

False equivalency as per usual, but I'm flattered you apparently keep my old posts on speed dial, lol. 

I stand by that post by the way, Nintendo needs to make more "blockbuster" titles like Mario Kart 8 that have all the fixings and give the impression to the consumer that they are really bringing their A-game to the table (like they did with N64 tent pole games).

That's why 14 years after the release of Majora's Mask, people still care about the game, whereas no one gives two farts about Wii Sports or Guitar Hero today. In the long term actual quality (rather than fads) is what creates long-term customers rather than gimmicks. 

The Wii U has so many problems, most centrally a fickle casual base who ditched Nintendo. Nintendo should have abandoned the ill-fated Wii brand entirely, they would be in a much better spot right now had they just used their 1 year headstart with a more sensibly designed enthusiast market console rather than thinking soccer moms and casuals would stay with them forever. 

Oh and I own both Captain Toad and Bayonetta 2 and they're both great games, neither is worth crapping on. The fact is whether you like it or not though the general gaming market is driven by violent action games. Look at any top 10 NPD of any month. Nintendo abandoning that market after Perfect Dark was always a mistake, any move to get some traction back with quality titles like Bayonetta 2 is welcome as far as I'm concerned. 

And by the way I'm not advocating a specific position in this thread, just asking an open question. 

Nintendo already targets both children, teens and adults.

I'd argue how valid that really is when prior to the New 3DS commercials during Better Call Saul/Walking Dead, almost like 80% of their marketing primarily featured kids or kids w/mom and dad over the last few years. 

Hate to say it, but adults simply don't respond to marketing aimed primarily at kids. 

And kids don't even really go for that as much either ... they want things are aimed at adults as much adults do (sometimes more). 

I think their marketing department basically went like this the last 5 years 

"Oh crap! We're losing casual adults to smartphones! We're losing money for the first time ever! Do something! Lets market to whats left of the Wii audience, gotta be kids and family right?"

That basically led to this (crap) marketing IMO:

https://www.youtube.com/watch?v=7dbGJieRaH0