I've just learned that Amazon has released a new Kindle Single today. It's a Portuguese translation of the Obama interview, and from what I can tell this is the Amazon's first Kindle Single in that language. This version of the interview was translated by Christiane Jost, and it was published by Amazon Crossing.
Amazon has been quietly expanding Kindle Singles into other languages, most recently with the launch of a German Kindle Single Store, but that's not their only endeavor. Last year Amazon also released a handful of Kindle Singles in Spanish.
There are 9 Kindle Singles available in Spanish. All appear to be translations from English, and they were all released on my birthday last year. At the moment there are also 54 Kindle Singles in German. It's not clear how many of those are translations but I suspect most were translated from English. The German Kindle Single Store isn't expected to start accepting new original content until this Fall.