I think the world needs virtual currencies especially bitcoins due to the system of economy right now is failure, system of fiat currency can not protect us from inflation, our system economy right now can not protect us from crisis condition, it is too old to be runned for couples decades later, so must there are new innovations on our economy system and the answer is only virtual currencies to fix all of this weakness.
Virtual currencies need by the world because it makes the transactions faster and wherever you are in just a matter of minutes products or services is paid. There's a lot of use by the virtual currencies even in the form of stocks exchange bitcoin is now listed one of a major currency thats why it's almost necessity to the world to have.