PHP - Unity3D Asset Store Publisher Feed. You must supply your own secret key to use this, a key is generated per publisher at https://publisher.assetstore.unity3d.com/info.html

unity3d-assetstore-publisher-feed.php

<?php 
include_once ( 'unity3d-assetstore.php' );
 
// Doesn't matter what is used for the publisher name,
// the key still points to only one publisher.
 
$authArray = array (
    'publisher' => '{PUBLISHER_NAME}' 
    'key' => '{PUBLISHER_KEY}',
);
  
$data = Unity3DAssetStore::getPublisherFeed($authArray['key'], $authArray['publisher']);

/**
 * @var $node SimpleXMLElement
 * @var $feed SimpleXMLElement
 * @var $channel SimpleXMLElement
 */
 
@$feed = new SimpleXMLElement($data);
@$channel = $feed->xpath('channel')[0];

// var_dump($feed);

echo "Channel\n\t";
echo "title: ", $channel->xpath("title")[0], "\n\t";
echo "link: ", $channel->link, "\n\t";
echo "description: ", $channel->description, "\n\t";
echo "language: ", $channel->language, "\n\t";
echo "copyright: ", $channel->copyright, "\n\t";
echo "pubDate: ", $channel->pubDate, "\n\t";
echo "ttl: ", $channel->ttl, "\n\t";
echo "image: ", $channel->xpath("image/url")[0], "\n\t";
echo "\n";

$items = $feed->xpath('channel/item');

while(list( , $node) = each($items)) {
    echo 'title: ', $node->title, "\n\t";
    echo 'link: ', $node->link, "\n\t";
    echo 'description: ', $node->description, "\n\t";
    echo 'guid: ', $node->guid, "\n\t";
    echo 'pubDate: ', $node->pubDate, "\n";
    echo "\n";
}

unity3d-assetstore.php

<?php
/**
 * Unity3DAssetStore Class
 */
class Unity3DAssetStore
{
    /**
     * static @var $PUBLISHER_API_FEED_URL string Base url for publisher feeds
     * static @var $PUBLISHER_API_FEED_ACTIVITY string
     * static @var $XSL_BEFORE string
     * static @var $XSL_AFTER string
     */

    public static $PUBLISHER_API_FEED_URL = 'https://publisher.assetstore.unity3d.com/feed/';
    public static $PUBLISHER_API_FEED_ACTIVITY = '/activity.rss';
    public static $XSL_BEFORE = '"/resources/xsl/rss/activity.xsl"';
    public static $XSL_AFTER = '"https://publisher.assetstore.unity3d.com/resources/xsl/rss/activity.xsl"';

    /**
     * @param $key
     * @param string $publisher (Optional)
     * @return string Feed Data
     */
    public static function getPublisherFeed($key, $publisher = "")
    {
        if ( $publisher === "" || strlen($publisher) < 1 ) $publisher = "publisher";

        $apiUrl = Unity3DAssetStore::$PUBLISHER_API_FEED_URL . $publisher . "/" . $key . Unity3DAssetStore::$PUBLISHER_API_FEED_ACTIVITY;

        $data = @file_get_contents($apiUrl);

        return ($data)
            ? str_replace (Unity3DAssetStore::$XSL_BEFORE, Unity3DAssetStore::$XSL_AFTER, $data)
            : $data;
    }
}

z results.xml

<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="/resources/xsl/rss/activity.xsl"?>
 
<rss version="2.0"
 xmlns:blogChannel="http://backend.userland.com/blogChannelModule"
>
 
<channel>
  <title>Unity Asset Store - Latest activity for Just Good Design</title>
  <link>http://u3d.as/3sY</link>
  <description>The latest activity for Just Good Design in the Unity Asset Store.</description>
  <language>en-us</language>
  <copyright>Unity Technologies</copyright>
  <pubDate>Sun, 24 Nov 2013 14:20:09 -0000</pubDate>
  <ttl>10</ttl>
  
  <image>
  <title>Unity</title>
  <url>http://download.unity3d.com/images/news/unity-logo.png</url>
  <link>http://www.unity3d.com/</link>
  </image>
  
  <item>
  <title>Review of package &#x22;Good Drop&#x22; by Just Good Design</title>
  <link>http://u3d.as/520</link>
  <description>&#x3C;h1&#x3E;test&#x3C;/h1&#x3E;&#x3C;p&#x3E;test&#x3C;/p&#x3E;</description>
  <guid isPermaLink="false">1145</guid>
  <pubDate>Tue, 29 Oct 2013 23:01:55 -0000</pubDate>
  </item>
  
  <item>
  <title>Reply to review of package &#x22;Good SVN&#x22; by Just Good Design</title>
  <link>http://u3d.as/4ea</link>
  <description>&#x3C;h1&#x3E;Reply from publisher&#x3C;/h1&#x3E;&#x3C;p&#x3E;testing&#x3C;/p&#x3E;</description>
  <guid isPermaLink="false">1124</guid>
  <pubDate>Tue, 29 Oct 2013 14:04:17 -0000</pubDate>
  </item>
</channel>
</rss>

Now the link is gone. In short for what it's doing (in case someone doesn't have access to PHP):

https://publisher.assetstore.unity3d.com/feed/<publisher-name>/<api-key>/activity.rss