@ Poll:
A little late, but anyway, I feel there are two franchises that absolutely have to be kept 100% in-house. These are 3D Mario, and Zelda. EAD just does these two series the best. So, I vote EAD. I just wouldn't dare to hand these two series, with flawless records if quality is concerned, off to someone else
For the handheld entries however, I okay with them handing some development off to another studios. They're less high-profile, so some experimentation is allowed. Retro would be a good fit I think. Capcom did a good job in the Oracle series, but their 'hands were held' (). I'm not too fond of the Minish Cap. Grezzo also proved they can do a good job in at least Zelda remakes with Ocarina of Time 3D and the Four Swords Anniversary Edition.