Language is a hot topic in D&D. You can refer back to my post from early last year, which also serves as a sort of bibliography of the many talking points surrounding the subject. I do think I came up with a rather clever solution to many of the perceived issues with languages in D&D, but it depends on both a more modern, skill-based system as well as a relatively "tight" list of just a few thematic languages, some of which are connected by common scripts.