And Numbers '09:
exports as CSV with comma as the field separator and period as the decimal separator in locales with period as the decimal separator;
exports as CSV with semicolon as the field separator and comma as the decimal separator in locales with comma as the decimal separator;
expects the same when opening a CSV file in the locales in question, so it can't handle files from a locale with a different choice of decimal separator;
offers no way of choosing different separators when opening or exporting.
I'll try it with the latest Numbers later.