Four developers Nintendo sould partner with

[sundin13]

Insomniac is an interesting choice that I haven't thought about...I'm not completely confident in them anymore due to their recent struggles but they have made some great games and I would be interested to see what they would do with Star Fox.
To take Star Fox in a different direction, Platinum Games would be the most obvious choice. While Insomniac I think would go towards a Ratchet and Clank type feel, Platinum would probably focus more on the flying aspect and make it like Vanquish in space...if that makes any sense.

For Metroid, I do not think Rockstead would be a good choice. I played Arkham Asylum and while it was a good game, it was not what I believe Metroid should head towards. I don't see any piece of those games that I think would work in the metroid universe (or that hasn't been done 100x better by Retro). I think Retro should stick with 3D Metroid games.
For 2D Metroid, I believe WayForward would be a great choice. I believe they have proved that they can make great 2D Metroid-esque games, as well as games like Aliens Infestation. With a great IP like Metroid, I think they could make a brilliant game.

I really like the idea of having Atlas make a Pokemon game. While I think it should be a spin off and not a main series game, it would be very interesting to see what they would do with the franchise.

I do not think CD Projekt RED should develop a Zelda game. In fact, I don't think anyone but Nintendo should develop a Zelda game. I do not believe that more "maturity" is necessary and I think that Nintendo would make a better Zelda game than anyone else. (radical spin offs like Hyrule Warriors are different)
I do very much like CD Projekt RED though and I would love to see them work on a new IP for the Wii U...but I doubt it will ever happen