looks cool
maybe add target="_blank" for open the link in the new tab/window?

Added

@mbabker @wilsonge Do you think we should add some escaping to the displayed data and the link?

Might be a good idea.

Something like ?:

                        <td>
                            <label for="cb<?php echo $i; ?>">
                                <?php echo $item->update_site_name; ?>
                                <br /><span class="small"><a href="<?php echo $item->location; ?>" target="_blank">
                                <?php echo $this->escape($item->location); ?></a></span>
                            </label>
                        </td>

We do have a similar code for update
https://github.com/joomla/joomla-cms/blob/staging/administrator/components/com_installer/views/update/tmpl/default.php#L120-L122 where the link is not escaped

test good, for me

Escaping the link when you use it as link doesn't make sense. But if you display it it makes sense. Your code looks fine and is the same like in com_installer where the display part is escaped as well

Escaping the link when you use it as link doesn't make sense

You are right. Thinking about it again, putting malicious content in that field would require the Super User to install an extension with a malicious update server URL. But if a hacker can get you to install their software on your server it's game over anyway. Brain fart. Please ignore me.

I had the same thought and came to same conclusion :)

Escaped display part. I guess this can now go RTC. Thanks for testing.