I put that on the To Do list
This can already be done with "Style & Edit Center Column" -> Content above Loop / Content below Loop, but should probably be easier because it is rather standard to have that
To do it now, Content above Loop:
(Taken from the Default theme)
PHP Code:
<?php $post = $posts[0]; // Hack. Set $post so that the_date() works. ?>
<?php /* If this is a category archive */ if (is_category()) { ?>
<h2 class="pagetitle">Archive for the ‘<?php single_cat_title(); ?>’ Category</h2>
<?php /* If this is a tag archive */ } elseif( is_tag() ) { ?>
<h2 class="pagetitle">Posts Tagged ‘<?php single_tag_title(); ?>’</h2>
<?php /* If this is a daily archive */ } elseif (is_day()) { ?>
<h2 class="pagetitle">Archive for <?php the_time('F jS, Y'); ?></h2>
<?php /* If this is a monthly archive */ } elseif (is_month()) { ?>
<h2 class="pagetitle">Archive for <?php the_time('F, Y'); ?></h2>
<?php /* If this is a yearly archive */ } elseif (is_year()) { ?>
<h2 class="pagetitle">Archive for <?php the_time('Y'); ?></h2>
<?php /* If this is an author archive */ } elseif (is_author()) { ?>
<h2 class="pagetitle">Author Archive</h2>
<?php /* If this is a paged archive */ } elseif (isset($_GET['paged']) && !empty($_GET['paged'])) { ?>
<h2 class="pagetitle">Blog Archives</h2>
<?php } ?>