Index: wp-includes/class-oembed.php
===================================================================
--- wp-includes/class-oembed.php	(revision 23391)
+++ wp-includes/class-oembed.php	(working copy)
@@ -47,7 +47,6 @@
 			'http://wordpress.tv/*'                              => array( 'http://wordpress.tv/oembed/',                       false ),
 			'#https?://(.+\.)?polldaddy\.com/.*#i'               => array( 'http://polldaddy.com/oembed/',                      true  ),
 			'#https?://(www\.)?funnyordie\.com/videos/.*#i'      => array( 'http://www.funnyordie.com/oembed',                  true  ),
-			'#https?://(www\.)?twitter.com/.+?/status(es)?/.*#i' => array( 'http://api.twitter.com/1/statuses/oembed.{format}', true  ),
  			'#https?://(www\.)?soundcloud\.com/.*#i'             => array( 'http://soundcloud.com/oembed',                      true  ),
 			'#https?://(www\.)?slideshare.net/*#'                => array( 'http://www.slideshare.net/api/oembed/2',            true  ),
 			'#http://instagr(\.am|am\.com)/p/.*#i'               => array( 'http://api.instagram.com/oembed',                   true  ),
Index: wp-includes/media.php
===================================================================
--- wp-includes/media.php	(revision 23391)
+++ wp-includes/media.php	(working copy)
@@ -1083,6 +1083,7 @@
 	if ( ! apply_filters( 'load_default_embeds', true ) )
 		return;
 	wp_embed_register_handler( 'googlevideo', '#http://video\.google\.([A-Za-z.]{2,5})/videoplay\?docid=([\d-]+)(.*?)#i', 'wp_embed_handler_googlevideo' );
+	wp_embed_register_handler( 'twitter', '#https?://(www\.)?twitter.com/.+?/status(es)?/.*#i', 'wp_embed_handler_twitter' );
 }
 
 /**
@@ -1110,6 +1111,14 @@
 }
 
 /**
+ * Twitter embed handler callback
+ */
+function wp_embed_handler_twitter( $matches, $attr, $url, $rawattr ) {
+	wp_enqueue_script( 'twitter-widgets', '//platform.twitter.com/widgets.js', array(), false, true );
+	return sprintf( '<blockquote class="twitter-tweet"><a href="%s">%s</a></blockquote>', esc_url( $url ), esc_html__( 'View embedded content' ) );
+}
+
+/**
  * {@internal Missing Short Description}}
  *
  * @since 2.3.0