One thing I find amazing when I study other languages is that there are certain ideas that don't translate exactly from one language to another. You can approximate them, but it's almost as if you can't think them without first thinking them in the appropriate language. Learning other languages isn't just good policy in this day and age; it also enables you to have more thoughts than you would otherwise.
So I'm all for projects to preserve the languages that are vanishing. Even if it's just a small number of people who can tell us about the disappearing ideas that human cultures have had, the work they're doing is worth it. Here's a short National Geographic clip on those researchers and the work they do.