They dont need third party support. They need more developing power and talent.

Can you imagine what Sony or Microsoft could have done with Pokemon if they owned the franchise?

it is already showing that Nintendo needs 3rd party support. the droughts in between 1st party games is really that big.

it needs 3rd parties and i'll tell you why...

...nintendo games aren't that good and lack universal appeal. so long as the console only plays nintendo games will will continue to draw in the same 10 million nintendo fans and no one else. diversity in lineup is what is needed to bring in diversity in consumer and therefore a reasonable sized userbase.

Is not going to be the same number of games probably, but it will be far superior number than now for WiiU, and they can continue to do some cheap games if the the console is able to make it look beautifull on the big screen, Imagine Luigi´s Mansion Dark moon at 1080p 60fps with antialiasing and some extra effects, it would look nice enough.

So they can:

1. Make all their games more ambitious than now
2. Keep doing some cheaper games as with their handhelds and some bigger games as with their homeconsoles

That brings up another problem, how would they price their games? Handheld games cost around 40€, and home console games cost around 50-60€. Would Nintendo unify the prices, or would they price each game individually?

There are still droughts even if you combine the librarys, the last game I can even remember is Splatoon and Puzzle Dragons a month or so ago, whens the next Nintendo game on 3DS or Wii U coming out?  

Edit: Yoshie WW released in Europe but not NA so there's still a massive drought here.

But why would you wanna play handheld style games on a big HD TV? And if every game is at least wii u quality its gonna have serious droughts again.

Either game droughts or just full of casual budget games
is the future for NX and if that's the case I'm out!

Good luck fitting Wii U into a 3DS's form factor alongside a decent screen, powerful battery etc for a $200 retail price in the near future.

That aside, you're right. A Nintendo handheld doesn't need massive third party support as we've seen from the 3DS. The thing about this model is that its essentially Nintendo giving up on the home console market.

Not entirely true, I can se 20M but not 10. Remember that Wii U lacks many Nintendo IP's like a real Zelda game, a real 3D Mario game, Fire Emblem, Luigi Mansion, F-Zero, Metroid, etc.

Fusion is a silly idea, always was. They will bring out a console and handheld running the same OS, that's it.