Add ability for users to send login credentials for private blogs.
Add absolute slug to post return value.
This is important since you need the absolute slug for nested pages.
Add post parent to return value.

This is useful for traversing hierarchy pages.
Add menu order to pages return value.

This is useful for sorting hierarchy menus.
Return all custom fields.

Some fields are necessary to be returned such as '_wp_page_template' for
determining the uniquely selected page template.