Very nice. I disagree with those who said it should have gone in discussion. Too much bolding, way, way too much bolding. Consider including links to, or discussion of Fluent In 3 Months or All Japanese All The Time

Speaking as someone with okay German and poor French who's currently learning Mandarin, gwern is correct, the returns for learning a language other than English that you don't need to use now are pretty low. It's really, really hard to get good at any language, and almost all multi-national workplace, English will be either the working language or acceptable (may not be true places where people speak French or places I don't think have enough people of enough nationalities to count as multi-national.)