jboss.xml validation: should I use DTD or XSD?

Issue

I would like some insight into the XML validation files that are provided to validate a jboss.xml descriptor.
On the JBoss wiki, I can see that both a DTD and a Schema exist for the 5.0 version. In front of the DTD, it says "use the XSD".
In the EAP distribution, the standardjboss.xml file uses the DTD and not the XSD.

• What are the differences between those two files?
• Do they validate the exact same content?
• Which one should we use?
• Why does the standardjboss.xml validate against a 5.0 DTD, when the server version is 5.1.x?