So we are sure that we will be taking our product internationally and will eventually need to internationalize it. How much internationalizing would you recommend we do as w
If you use test data, use non-English (e.g.: Russian, Polish, Norwegian etc) strings. Encoding peeks it's little ugly head at every corner. If not in your own libraries, then in external ones.
I personally favor Russian because although I don't speak a word Russian (despite my name's origin) it has foreign chars in it and it takes way more space then English and therefor tests your spacing too.
Don't know if that is something language specific, or just because our Russian translator likes verbose strings.