Today is my DD's birthday (#12) and she is enamored with Japanese. She watches all kinds of anime and downloads Japanese music (and seems to sing-along) all of the time. For her birthday, she received 'how to speak Japanese' CD's and word books. She's been listening to lessons and reading her books. We're going to WDW in late June and I've given her a goal to be able to speak a few words of Japanese in the Japan pavillion. It'll be interesting to see if she will be able to pull off a phrase or two. She picks things up pretty quickly so I'm pretty confident she'll pull it off.
And yes.......each country is staffed with CM's from that country, so native languages are spoken everywhere in World Showcase.