After upgrading from JBossWS 1.2.1 to JBossWS 2.0 I made these changes:

• WebContext is now in package org.jboss.wsf.spi.annotation
• ANT task <wsprovide> changed to class org.jboss.wsf.spi.tools.ant.WSProvideTask

In build.xml the target looks as follows:
<taskdef name="wsprovide" classname="org.jboss.wsf.spi.tools.ant.WSProvideTask">
<classpath refid="wsprovide.classpath"/>
</taskdef>
<wsprovide
fork="false"
keep="true"
destdir="${gen.dir}"
genwsdl="true"
verbose="true"
sei="de.hska.ws.KundenverwaltungServiceBean">
<classpath>
<pathelement path="${classes.dir}"/>
</classpath>
</wsprovide>

When executing this target I get this stack trace:
java.lang.IllegalArgumentException: Failed to wrap classloader
at org.jboss.wsf.spi.tools.ant.WSProvideTask.getClasspathLoader(WSProvideTask.java:185)
at org.jboss.wsf.spi.tools.ant.WSProvideTask.executeNonForked(WSProvideTask.java:201)
at org.jboss.wsf.spi.tools.ant.WSProvideTask.execute(WSProvideTask.java:233)
at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288)
at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:105)
at org.apache.tools.ant.Task.perform(Task.java:348)
at org.apache.tools.ant.Target.execute(Target.java:357)
at org.apache.tools.ant.Target.performTasks(Target.java:385)
at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1329)
at org.apache.tools.ant.helper.SingleCheckExecutor.executeTargets(SingleCheckExecutor.java:38)
at org.apache.tools.ant.Project.executeTargets(Project.java:1181)
at org.apache.tools.ant.taskdefs.Ant.execute(Ant.java:416)
at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288)
at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:105)
at org.apache.tools.ant.Task.perform(Task.java:348)
at org.apache.tools.ant.Target.execute(Target.java:357)
at org.apache.tools.ant.Target.performTasks(Target.java:385)
at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1329)
at org.apache.tools.ant.helper.SingleCheckExecutor.executeTargets(SingleCheckExecutor.java:38)
at org.apache.tools.ant.Project.executeTargets(Project.java:1181)
at org.apache.tools.ant.taskdefs.Ant.execute(Ant.java:416)
at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288)
at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:105)
at org.apache.tools.ant.Task.perform(Task.java:348)
at org.apache.tools.ant.Target.execute(Target.java:357)
at org.apache.tools.ant.Target.performTasks(Target.java:385)
at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1329)
at org.apache.tools.ant.helper.SingleCheckExecutor.executeTargets(SingleCheckExecutor.java:38)
at org.apache.tools.ant.Project.executeTargets(Project.java:1181)
at org.apache.tools.ant.taskdefs.Ant.execute(Ant.java:416)
at org.apache.tools.ant.taskdefs.CallTarget.execute(CallTarget.java:105)
at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288)
at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:105)
at org.apache.tools.ant.Task.perform(Task.java:348)
at org.apache.tools.ant.Target.execute(Target.java:357)
at org.apache.tools.ant.Target.performTasks(Target.java:385)
at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1329)
at org.apache.tools.ant.Project.executeTarget(Project.java:1298)
at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
at org.apache.tools.ant.Project.executeTargets(Project.java:1181)
at org.apache.tools.ant.Main.runBuild(Main.java:698)
at org.apache.tools.ant.Main.startAnt(Main.java:199)
at org.apache.tools.ant.launch.Launcher.run(Launcher.java:257)
at org.apache.tools.ant.launch.Launcher.main(Launcher.java:104)
Caused by: java.net.MalformedURLException: unknown protocol: c
at java.net.URL.<init>(URL.java:574)
at java.net.URL.<init>(URL.java:464)
at java.net.URL.<init>(URL.java:413)
at org.jboss.wsf.spi.tools.ant.WSProvideTask.getClasspathLoader(WSProvideTask.java:181)