We definitely need to see more of Treehouse. It would be cruel to restrict them to E3 only! Perhaps give them a regular section in Nintendo Directs. Like, Iwata/Shibata/Reggie talks a little bit about a game, then hands over to Treehouse for a demonstration and more information.
I'd like to see Nintendo Direct being followed by a Treehouse in depth look. Say a half hour direct with announcements/trailers and then a 1 hour Treehouse show with live gameplay of select games shown in the direct.