previous_post_link/next_post_linkのa要素にtitle属性で記事タイトルを入れる
wp-includes/link-template.php 1269行目(ver2.9.2)
[code language=”php”]
$string = ‘<a href="’.get_permalink($post).’" rel="’.$rel.’">’;
↓
$string = ‘<a href="’.get_permalink($post).’" rel="’.$rel.’" title="’.$title.’">’;
[/code]