When adding a server runtime for the first time in a workspace there is an error that appears for a second and then disappears again and everything seems ok.

See the screencast here: http://screencast.com/t/3kIRPSUs

The error says:
'Add Server XPath Details' has encountered a problem.

An internal error occurred during: "Add Server XPath Details"

Note that this happens on the M5 build with both EAP 6.0 DR11 and JBoss AS 7.1 CR1b

This is in the log:

!ENTRY org.eclipse.core.jobs 4 2 2012-01-25 10:37:32.660
!MESSAGE An internal error occurred during: "Add Server XPath Details".
!STACK 0
java.lang.NullPointerException
at org.jboss.ide.eclipse.as.core.extensions.descriptors.XPathQuery.setEffectiveBaseDir(XPathQuery.java:111)
at org.jboss.ide.eclipse.as.core.extensions.descriptors.XPathQuery.setCategory(XPathQuery.java:254)
at org.jboss.ide.eclipse.as.core.extensions.descriptors.XPathCategory.addQuery(XPathCategory.java:105)
at org.jboss.ide.eclipse.as.core.extensions.descriptors.XPathModel.loadDefaults(XPathModel.java:297)
at org.jboss.ide.eclipse.as.core.extensions.descriptors.XPathModel.handleAddJBoss7XPaths(XPathModel.java:90)
at org.jboss.ide.eclipse.as.core.extensions.descriptors.XPathModel.access$0(XPathModel.java:89)
at org.jboss.ide.eclipse.as.core.extensions.descriptors.XPathModel$1.run(XPathModel.java:81)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)