Nintendo spent a lot of time talking about the Miiverse in today's Nintendo Direct promising updates and new features in the near future. It also announced a new Miiverse app for smartphones, detailed back in June, would be coming this spring.
Nintendo president Satoru Iwata said that Miiverse will be expanding to include user created communities, and more than one official community for games. He also promised new usability features and filters so comments don't get lost so quickly in the Miiverse stream of consciousness. He also said that the upcoming Pikmin 3 would allow the Wii U GamePad to act as a camera to take pictures of the game and allow players to upload images directly to Miiverse.
Not much was said about the upcoming app, other than it will basically be a Miiverse browser with more functionality coming later.