In 3.4 you no longer need any PHP…

In 3.4, you no longer need any PHPPHP PHP (recursive acronym for PHP: Hypertext Preprocessor) is a widely-used open source general-purpose scripting language that is especially suited for web development and can be embedded into HTML. to customize the defaults for start of week, feed language, or default timezone. (You would have hooked into populate_options for these.)

start_of_week and timezone_string/gmt_offset are now translatable, and rss_language is gone (it uses the site’s localeLocale Locale = language version, often a combination of a language code and a region code, for instance es_MX denotes Spanish as it’s used in Mexico. A list of all locales supported by WordPress in, now).

I’ve created a page here that outlines all changes to 3.4 so far, including the details for how to set these defaults: Important Changes for WordPress 3.4. I will update it as more changes happen.