The Australian curriculum does not support learning a language as do say our European neighbors efforts. They are to soley speak that language in class, learn the history, geography, culture of the chosen language. That is truly being educated in a language.
There are some schools do have language programs that stretch across other classes. My school for example did when I went to school but I don't think they do anymore. It was called German immersion and things like history, social science and science were taught completely in German.

I was just talking about the articles Onyx posted. They showed the advantages from being bilingual, but IMO taking a language class at school isn't going to make you bilingual so is not going to have the same effect IYKWIM?
How does one become bilingual if they don't learn a second language? You have to start somewhere and 12yrs of schooling is a long time to be exposed to a language. It is how people in Europe become bilingual so it is possible.

All that said I wouldn't be forcing my children to take a language against their will but I would be encouraging and supporting it. I did not initially appreciate the piano lessons my parents encouraged until I came to learn other things I enjoyed (drums, flute and trumpet) and realised how it built the foundation to make those things a lot easier! I think language is similar, it sets up a good base to be worked off.

I think you can enjoy learning anything with the right people and environment though. I think sometimes passions need not be something that was always internally bubbling but can be inspired by the people who introduce them to us in a way we can relate to. I will always be following the lead of my children but I think that involves exposing them to many different things so they can know what sort of options there are to choose from in the first place.