Google AdWords has added support for Google Translator Toolkit. This means you can now translate your keywords and have ads appear to global audiences in their language.
However, Search Engine Watch columnist Andy Atkins-Krüger warned about the pitfalls of keyword translation in an August post entitled Translating Keywords Should Never EVER Happen. Atkins-Kruger made the good point that while serving up ads to audiences in their language is important, simple translation is risky.
The reason is that this planet is so culturally diverse. Even countries that share the same language often have their regional nuances. Language in and of itself does not contain a culture.
The best way to serve up foreign language ads is through human translation by someone who understands the culture of the country that's being targeted. While Google's intentions appear to be good in offering this new feature, it should be used with great caution.