Soon when some countries will accept bitcoin as a payment.
I think bitcoin is already international currency because we can spend it online shops in different country, and soon i think more adoption will come into bitcoin and more online stores will include bitcoin as mode of payment.
Yes bitcoin has already became an international currency as people from different countries are using it and now it has also started to get global exposure from different corners of the world and soon we will be seeing many more people and companies getting into bitcoins which will give bitcoin recognition at international level.