It wouldn't be difficult to put together a list of first-party Nintendo developers, but navigating the second and third-party relationships would take some serious effort.

Are you up to the challenge? I believe in you

Well I've already got the first-party done so why not?

Nice list. Looking forward to see what titles Sony and MS show at E3. There were rumors that Sumo Digital (Sonic & All-Stars Racing Transformed) was working on LBP3. Has that been rejected?

http://www.vg247.com/2013/02/07/littlebigplanet-3-in-works-at-sumo-digital-rumour/

Updated it using your list :D

A more detailed and comprehensive list based on our desire to compare Wii U with PS4/X1.

First-Party Teams: 18
First-Party Teams of Consequence: 16
First-Party Teams Confirmed to Be Working On Games For Wii U: 9
Number of First-Party Wii U Games In-Development: 7 (I count SMT as second-party and Game & Wario is jointly-developed)

1-UP Studio – Fantasy Life (co-developer, already out in Japan, may be released internationally)
HAL Laboratory – Unknown
Intelligent Systems – Game & Wario (co-developer), Shin Megami Tensei X Fire Emblem (co-developer)
Monolith Soft – X, Untitled 3DS Project
Nd Cube – Mario Party 3DS (presumably)
Nintendo EAD Comprehensive Group – N/A (more or less an oversight team last credited for Super Mario 64 DS)
Nintendo EAD Group 1 – Mario Kart U
Nintendo EAD Group 2 – Animal Crossing: New Leaf
Nintendo EAD Group 3 – The Legend of Zelda: A Link to the Past II, The Legend of Zelda: Wind Waker HD, The Legend of Zelda (Wii U)
Nintendo EAD Group 4 – Pikmin 3, New Super Luigi U
Nintendo EAD Group 5 - Wii Fit U
Nintendo EAD Tokyo 1 - Unknown
Nintendo EAD Tokyo 2 - Untitled 3D Mario Game (Wii U)
Nintendo NSD - Unknown (low profile dev team better known for hardware addons)
Nintendo NST - Unknown
Nintendo SDD - Unknown
Nintendo SPD - Game & Wario (co-developer)
Retro Studios - Untitled Wii U Project

Second-Party Wii U Devs: 5
Second-Party Wii U Games: 8

Namco Bandai - Super Smash Bros. 4
Sega - Mario & Sonic at the Olympic Winter Games, Sonic: Lost World, Untitled Sonic Game
Platinum Games - The Wonderful 101, Bayonetta 2
Atlus - Shin Megami Tensei X Fire Emblem (co-developer)
Good-Feel - Yarn Yoshi (working title)

The second-party list is subject to change based on further research. It also doesn't include 3DS partnerships at this time, but it can be attempted if there is enough demand for them.

Major overhaul after e3 enjoy ;)