I think a feature like this could be amazing. Essentially, when you follow them you get notifications for whenever they release a new blog, upload a new photo, or make a new painting (if on 3DSPaint you only see paintings there whereas DSiPaint users dont get 3DSPaint notifications). This could also apply to friends. It may require an all notifications button at the bottom. In My Zone you could hide follower count and prevent certain notifications if you want too or changing how it acts. Instead of all blogs, only featured blogs you get notified of for example. It seems really useful of a feature even if only for friends.