Often multilingual sites will use URLs contructed with non-compliant country region codes. When using Drupal and i18n / Internationalization, this can be a problem since i18n_hreflang relies on the language codes as set (manually) within Drupal by the webmaster. In such situations it could be preferable to resolve this with code rather than changing the URL pattern.
Drupal 8 has been in the works for some time now, and looks pretty exciting. We’re particularly excited about web services becoming part of Drupal core, rather than being something you can add on. We have built custom web services applications for Joomla & SouthWare e-commerce sites, but would love to be able to do that more easily in Drupal too.