This should work - just fill in your info in the hardcoded tags. It still doesn't validate due to those iTunes errors, but it works in all aggregators including iTunes, so I don't get it. I will continue tweaking it. I've been using this for days and it works great.
-------------- Replace your wp-rss2.php with this below -----
<?php
if (empty($feed)) {
$blog = 1;
$feed = 'rss2';
$doing_rss = 1;
require('wp-blog-header.php');
}
header('Content-type: text/xml; charset=' . get_settings('blog_charset'), true);
$more = 1;
?>
<?php echo '<?xml version="1.0" encoding="'.get_settings('blog_charset').'"?'.'>'; ?>
<rss version="2.0"
xmlns:content="http://purl.org/rss/1.0/modules/content/"
xmlns:wfw="http://wellformedweb.org/CommentAPI/"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:itunes="http://www.itunes.com/DTDs/Podcast-1.0.dtd"
>
<channel>
<title><?php bloginfo_rss('name'); ?></title>
<link><?php bloginfo_rss('url') ?></link>
<description><?php bloginfo_rss("description") ?></description>
<pubDate><?php echo mysql2date('D, d M Y H:i:s +0000', get_lastpostmodified('GMT'), false); ?></pubDate>
<generator>http://wordpress.org/?v=<?php bloginfo_rss('version'); ?></generator>
<language><?php echo get_option('rss_language'); ?></language>
<managingEditor>email@domain.com (John Doe)</managingEditor>
<copyright>Copyright 2005, My Podcast</copyright>
<category>Comedy</category>
<image>
<url>http://www.mydomain.com/myimage.gif</url>
<link>http://www.mydomain.com</link>
<title>My Podcast</title>
<width>144</width>
<height>144</height>
</image>
<itunes:subtitle><?php substr(bloginfo_rss("description"), 0, 255); ?></itunes:subtitle>
<itunes:summary>A long description of my podcast</itunes:summary>
<itunes:author>John Doe</itunes:author>
<itunes:owner>
<itunes:name>John Doe</itunes:name>
<itunes:email>email@domain.com</itunes:email>
</itunes:owner>
<itunes:explicit>Yes</itunes:explicit>
<itunes:category text="Comedy" />
<itunes:category text="Talk Radio" />
<itunes:category text="Audio Blogs" />
<itunes:link rel="image" type="video/jpeg" href="http://www.domain.com/itunesimage.jpg">My Podcast</itunes:link>
<?php $items_count = 0; if ($posts) { foreach ($posts as $post) { start_wp(); ?>
<item>
<title><?php the_title_rss() ?></title>
<link><?php permalink_single_rss() ?></link>
<comments><?php comments_link(); ?></comments>
<pubDate><?php echo mysql2date('D, d M Y H:i:s +0000', get_post_time('Y-m-d H:i:s', true), false); ?></pubDate>
<dc:creator><?php the_author() ?></dc:creator>
<?php the_category_rss() ?>
<itunes:subtitle><?php substr(the_excerpt_rss(),0, 255); ?></itunes:subtitle>
<itunes:summary><?php the_content_rss(); ?></itunes:summary>
<itunes:author>John Doe</itunes:author>
<itunes:explicit>Yes</itunes:explicit>
<itunes:category text="Comedy" />
<itunes:category text="Talk Radio" />
<itunes:category text="Audio Blogs" />
<guid><?php the_permalink($id); ?></guid>
<?php if (get_settings('rss_use_excerpt')) : ?>
<description><![CDATA[<?php the_excerpt_rss() ?>]]></description>
<?php else : ?>
<description><![CDATA[<?php the_excerpt_rss() ?>]]></description>
<?php if ( strlen( $post->post_content ) > 0 ) : ?>
<content:encoded><![CDATA[<?php the_content('', 0, '') ?>]]></content:encoded>
<?php else : ?>
<content:encoded><![CDATA[<?php the_excerpt_rss() ?>]]></content:encoded>
<?php endif; ?>
<?php endif; ?>
<wfw:commentRSS><?php echo comments_rss(); ?></wfw:commentRSS>
<?php rss_enclosure(); ?>
</item>
<?php $items_count++; if (($items_count == get_settings('posts_per_rss')) && empty($m)) { break; } } } ?>
</channel>
</rss>