I am using the xdoclet1.2 beta. Don't see any mention of this task. Maybe the version in CVS ??
If you look here:
under src/tools there is a class called
This appears to be the task that is used to gen the web-services.xml file. I have not tried it yet however...I wonder if anything else is required besides this file and xdoclet....
It seems to be in the jboss version in cvs. Get jboss-all and look at "thirdparty/xdoclet/jboss.net".