The default strings used for <input type="submit">, <input type="reset">, the <isindex> prompt and the file upload control (button and placeholder) are currently localized strings that follow the localization of the Safari UI, regardless of the language of the page. Instead, they should be localized using the control's lang attribute (or the inherited language code, see http://www.w3.org/TR/html401/struct/dirlang.html#h-8.1.2 ), with the UI localization as a fallback.
Personally, I would prefer to see the titles of these controls in a language that I understand, even if I don't understand the language of the page itself. But what do other browsers do?