I remember doing it before, so I guess I'm missing something here. XMLNode's nodeType property only support ELEMENT_NODE and TEXT_NODE, and if I try to add the CDATA section to the XMLNode as a string it get escaped.
var node:XMLNode = new XMLNode(3, "<![CDATA[some text and <tags> here]]>");
What I get is a TEXT_NODE with the following value:
< ;![CDATA[some text and < ;tags> ; here]]> ;
which isn't even a valid value for a TEXT_NODE