WordPress is already going through a measured factoring approach. Themes were ported over from a mishmash of procedural calls into the WP_Theme object in versi

WordPress is already going through a measured factoring approach. Themes were ported over from a mishmash of procedural calls into the WP_Theme object in version 3.4. Posts (and pages, custom post types, etc) were ported over from an associative array and various procedural calls into the WP_Post object in 3.5. But WordPress does - and likely always will - work to retain backwards compatibility so that existing themes and plugins won't choke after a core update. So even when newer APIs and refactored objects exist, its up to individual developers to 1) learn about them and 2) start using them.