You should have a feature where you can face off against another opponent of an equal skill and/or where you can actually dance with an individual. You should show the person messing up when they miss something, etc. It could be a cool way to up the social and the amount of players!

If you introduce a one on one dance feature, the social rate would go to a whole new level. People will feel a little more competative. I had in mind something like a two opponents/friends facing each other and being able to see where and when the opposing person made a mistake. You could put a \\"HOW WELL DID YOU DO?\\" page after a competetive match and a personal chat (without having to dance out each sentence) after a friendly dance (with a time limit if you want them to keep dancing). People can get a little more connected this way.