Very nice! Ever heard a vocaloid sing in Spanish or Russian? Surprisingly good stuff, despite not being designed around it.
An example. (youtube.com)
Miku always sounds cute to me, but I'm not sure on the pronunciation. I listened to some Miku singing English songs before the English voice bank was released, it was basically Engrish.
Miku cover of Heaven is a Place on Earth. https://youtu.be/HATpOha7DFg
(post is archived)