Mage::helper('core')->formatDate(null, Mage_Core_Model_Locale::FORMAT_TYPE_SHORT, false);
The last parameter allows for time to be hidden:
public function formatDate($date = null, $format = Mage_Core_Model_Locale::FORMAT_TYPE_SHORT, $showTime = false)
That is very annoying of Magento really, to provide a wrapper to a method but not provide full access. Why they haven't written the method like the following I don't know...
public function getCreatedAtFormated($format, $showTime = true)
{
return Mage::helper('core')->formatDate($this->getCreatedAtStoreDate(), $format, $showTime);
}