Update: The new UI was pulled before the release of 3.6 and its development will continue in a plugin until it’s ready for core.
WordPress 3.6 is currently in beta, and is set to come with a new post formats interface that’s right in our faces. But sometimes we don’t need post formats. Luckily we have two options. We can either hide it, or we can disable it entirely.
Hiding the Post Formats UI
Hiding it is easy. Just uncheck the box in Screen Options.
Disabling the Post Formats UI
But what if we want it completely disabled? That’s pretty easy too. WordPress offers a filter to disable it, and it can be done with just a single line of code.
add_filter( 'enable_post_format_ui', '__return_false' );
Easy enough, right?