Languages that would be good to know (since nanshork asked): English (Duh), probably Spanish, Chinese, really any major languages. Basically, if you want to spend skill points on other languages, then you'll get to use them. If you don't, you may find that English has suddenly become much more prevalent around the world. If you want to decide on a language that you all know, but that most people would not so that you can talk secretly right in front of people, I think that's a great idea.
Also, I'm going to start this on Monday, since I will be gone this weekend, so check the game thread then. (I would start sooner, but I don't want to be gone right after we start.)