Well, export_xhtmlbody is really close what I look for. But what I mean is something like Dublin-Core:
http://dublincore.org/
What I was looking for is:
<?xml version="1.0" encoding="UTF-8" ?>
<wiki-page>
<meta-data>
<!-- Put some meta like in DC format in here //-->
</meta-data>
<body>
<!-- Put XML nodes here that represent headers with their titles and texts below it. //-->
</body>
</wiki-page>