[mdcox]

Historical Baggage. If someone starts speaking Russian, we've got a whole cultural idea of what it means for them to be speaking that language. I expect they wouldn't want to tint character personalities with biases from reality.

[billforsternz]

Which is why you wouldn't pick Russian. You need something more obscure and exotic sounding, that the vast majority of the audience wouldn't recognize. There are a lot of such languages. Possibly Lithuanian was too conservative. Basque anyone? For Dothraki you really just need something really alien sounding.

Early in Game of Thrones when Khaleesi (sp?) hooked up with the Dothraki warrior guy ("you are my moon" etc.) I would infuriate the office GoT geek by my inability to remember any of the names in general, and my humorous (to me) habit of referring to said warrior as "the Klingon dude" in particular. To me if he looks like a Klingon and sounds like a Klingon...