if you google "21$ in bitcoin" immediately there is a exchange rate. Just like any other currency or formula you can google. Guess what? The world knows about bitcoin; its capabilities has been shown. Guess what? The world is NOT impressed by bitcoin, and uninterested. Bitcoin is disliked, and is not useful to 95% of the population.
I was around in 2011, and we dreamed of this day, where the world has been exposed to bitcoin. As the saying goes "be careful what you wish for", there really isn't that much going on for bitcoin, but furthermore, the future of bitcoin.
Bitcoin is the Segway of money. It works, it's moderately useful, and it's not going to change the world.