Index: src/wp-includes/ms-functions.php
===================================================================
--- src/wp-includes/ms-functions.php	(revision 31264)
+++ src/wp-includes/ms-functions.php	(working copy)
@@ -811,7 +811,7 @@
 	if ( !is_subdomain_install() || get_current_site()->id != 1 )
 		$activate_url = network_site_url("wp-activate.php?key=$key");
 	else
-		$activate_url = "http://{$domain}{$path}wp-activate.php?key=$key"; // @todo use *_url() API
+		$activate_url = set_url_scheme( "http://{$domain}{$path}wp-activate.php?key=$key" ); // @todo use *_url() API
 
 	$activate_url = esc_url($activate_url);
 	$admin_email = get_site_option( 'admin_email' );
@@ -841,7 +841,7 @@
 			$domain, $path, $title, $user, $user_email, $key, $meta
 		),
 		$activate_url,
-		esc_url( "http://{$domain}{$path}" ),
+		esc_url( set_url_scheme( "http://{$domain}{$path}" ) ),
 		$key
 	);
 	// TODO: Don't hard code activation link.
Index: src/wp-signup.php
===================================================================
--- src/wp-signup.php	(revision 31264)
+++ src/wp-signup.php	(working copy)
@@ -370,10 +370,15 @@
  * @param array $meta Any additional meta from the 'add_signup_meta' filter in validate_blog_signup()
  */
 function confirm_another_blog_signup( $domain, $path, $blog_title, $user_name, $user_email = '', $meta = array() ) {
+	$blog_url = set_url_scheme( "http://{$domain}{$path}" );
 	?>
-	<h2><?php printf( __( 'The site %s is yours.' ), "<a href='http://{$domain}{$path}'>{$blog_title}</a>" ) ?></h2>
+	<h2><?php printf( __( 'The site %s is yours.' ), sprintf( '<a href="%s">%s</a>', $blog_url, $blog_title ) ) ?></h2>
 	<p>
-		<?php printf( __( '<a href="http://%1$s">http://%2$s</a> is your new site. <a href="%3$s">Log in</a> as &#8220;%4$s&#8221; using your existing password.' ), $domain.$path, $domain.$path, "http://" . $domain.$path . "wp-login.php", $user_name ) ?>
+		<?php printf( __( '%1$s is your new site. <a href="%2$s">Log in</a> as &#8220;%3$s&#8221; using your existing password.' ),
+			sprintf( '<a href="%s">%s</a>', $blog_url, $blog_url ),
+			set_url_scheme( "http://{$domain}{$path}wp-login.php" ),
+			$user_name
+		); ?>
 	</p>
 	<?php
 	/**
@@ -622,8 +627,9 @@
  * @param array $meta Any additional meta from the 'add_signup_meta' filter in validate_blog_signup()
  */
 function confirm_blog_signup( $domain, $path, $blog_title, $user_name = '', $user_email = '', $meta = array() ) {
+	$blog_url = set_url_scheme( "http://{$domain}{$path}" );
 	?>
-	<h2><?php printf( __( 'Congratulations! Your new site, %s, is almost ready.' ), "<a href='http://{$domain}{$path}'>{$blog_title}</a>" ) ?></h2>
+	<h2><?php printf( __( 'Congratulations! Your new site, %s, is almost ready.' ), sprintf( '<a href="%s">%s</a>', $blog_url, $blog_title ) ) ?></h2>
 
 	<p><?php _e( 'But, before you can start using your site, <strong>you must activate it</strong>.' ) ?></p>
 	<p><?php printf( __( 'Check your inbox at <strong>%s</strong> and click the link given.' ),  $user_email) ?></p>