In Miiverse you can now do the following…

“Wii U version and Web version You can now attach tags such as “Question” and “Impressions” to your Miiverse posts. Any tags you attach yourself will be coloured blue. (As before, posts made from games will have green tags.) The tags you can choose vary by community, but now that you can filter posts by tag, it’s much easier to find the post you’re looking for!”

“Wii U version only The character limit for messages to other users has been changed to 200. In June, we changed the character limit for posts and comments from 100 to 200, and now we’ve carried over this change to also apply to messages.”

There were also changes to the code of conduct.