C:\devel\ws\private\jboss-head\build\output\jboss-5.0.0.Beta\bin>twiddle info "jboss.jca:name=DefaultDS,service=ManagedC
onnectionPool"
Exception in thread "main" java.lang.NoClassDefFoundError: org/jboss/util/NestedException
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)

It is probably some fallout from the common package separation