Starting at line 957 of class.tx_ttnews.php:

// JEA: Wed Sep  6 17:26:25 CDT 2006
// This is substituted when there is no news in the list ... and so I want to do something better
// than to just display "no news."  I want it to be templateable!!!
$noNewsMsg = $this->getNewsSubpart($this->templateCode, $this->spMarker('###TEMPLATE_NONEWS###'));
$content .= $this->cObj->substituteMarkerArrayCached($noNewsMsg, $markerArray);
// but if there is _still_ nothing to display, then display, _something_. :)
if (!$content) {
        $content .= $this->local_cObj->stdWrap($this->pi_getLL('noNewsToListMsg'), $this->conf['noNewsToListMsg_stdWrap.']);

}

I should go back at a later date and fix this to be a submittable patch.  I don't understand any reason why people _wouldn't_ want this to be modifiable by template.  It just doesn't look good in a heavily-modified news list to have an unstyled "no news in list" message appear.  :-)