I checked the 'content' region, being one of the prerequisite regions and it is present and referenced in the sky.info file as well as in the page.tpl.php.
That is: (in sky.info file)
regions[content] = Main content
(in page.tpl.php file)
<div id="content"><?php print render($page['content']); ?></div>
However, when I go into the 'block' setup GUI page, from the regions dropdown, I can not see the 'content' region option.
Any idea as to why its not visible would be great. Cheers