[ Late answer: This is only valid/useful if you want to avoid using a get_text filter -- I always worry about performance using them ]
In 3.5.1, the Formats meta box is rendered on line 305 ( post_format_meta_box ) of "wp-admin/includes/meta-boxes.php".
This function calls "get_theme_support('post-formats')" located in "wp-includes/theme.php" and returns the original add_theme_support value inserted by the theme -- in this case, the array of post formats.
Theres no filter on the return value, just "return $_wp_theme_features[ $feature ];"
An alternative, if you want to avoid using Javascript/jQuery, it is possible to substitute your own Formats meta box by duplicating the code from the post_format_meta_box function with your own custom code:
function add_custom_formats_metabox( )
{
remove_meta_box( 'formatdiv' , 'post' , 'side' );
add_meta_box( 'my-formatdiv', 'Format' , 'render_custom_formats_metabox', 'post', 'side', 'core' );
}
function render_custom_formats_metabox( $post, $box ) {
if ( current_theme_supports( 'post-formats' ) && post_type_supports( $post->post_type, 'post-formats' ) ) :
$post_formats = get_theme_support( 'post-formats' );
if ( is_array( $post_formats[0] ) ) :
$post_format = get_post_format( $post->ID );
if ( !$post_format )
$post_format = '0';
if ( $post_format && !in_array( $post_format, $post_formats[0] ) )
$post_formats[0][] = $post_format;
?>
<div id="post-formats-select">
<input type="radio" name="post_format" class="post-format" id="post-format-0" value="0" <?php checked( $post_format, '0' ); ?> /> <label for="post-format-0"><?php _e('Standard'); ?></label>
<?php
foreach ( $post_formats[0] as $format ) :
// implement your own labeling logic here...
$label = $format === 'chat' ? 'Discussion' : get_post_format_string( $format ) ;
?>
<br /><input type="radio" name="post_format" class="post-format" id="post-format-<?php echo esc_attr( $format ); ?>" value="<?php echo esc_attr( $format ); ?>" <?php checked( $post_format, $format ); ?> /> <label for="post-format-<?php echo esc_attr( $format ); ?>"><?php echo esc_html( $label ); ?></label>
<?php endforeach; ?><br />
</div>
<?php endif; endif;
}
add_action( 'add_meta_boxes' , 'add_custom_formats_metabox' );