Nintendo has announced on their official Miiverse page that there are several changes incoming to the community service. According to Nintendo this "big" redesign is incoming this very summer.
The new features for players include a private screenshot album that'll store up to 100 shots, a Play Journal that can be opened while playing a game to write up your experiences - there'll also be a similar Journal community section to compare game experiences, though this'll replace the current Activity feed (but you'll be able to post up to 30 posts per day). Another new community feature will focus on player drawings.
Check out the official site for more.