You can retrieve a collection of authors using the following code:
<?php $authors = Mage::getResourceModel('wordpress/user_collection') ?>
You can then list through these as follows:
<?php $authors = Mage::getResourceModel('wordpress/user_collection') ?>
<?php if (count($authors) > 0): ?>
<ul>
<?php foreach($authors as $author): ?>
<li>
<a href="<?php echo $author->getUrl() ?>"><?php echo $author->getDisplayName() ?></a>
</li>
<?php endforeach; ?>
</ul>
<?php endif; ?>