Create private Twitter rank lists
Recently Twitter has taken action to prevent people from getting followers just to inflate their ego, or to spam them. From a business perspective, more followers is good if managed responsibly.
What I would like to suggest, which would be of particular interest to businesses, is the ability to create a private list of selected users - business rivals - so you can manage your number of followers compared to them.
This will be of most interest to small local businesses, especially if Twitter explains better how it works so that more people get it and join the conversation.