if you check out the API docs at http://pubsvn.ez.no, you can see that this class has a method <i>mainNode()</i> which returns the main node of the object. This node i an instance of the eZContentObjectTreeNode class which has the method </i>urlAlias.
Also usefull is the <i>fetchDataMap</i>method, that according to the API is <i>a map with all the content object attributes where the keys are the attribute identifiers.</i>