Using Olamy's work on integration with maven3 and the cobertura-plugin I get the following exception:
org.apache.maven.InternalErrorException: Internal error: java.lang.ClassCastException: [Lorg.codehaus.plexus.configuration.PlexusConfiguration; cannot be cast to [Lorg.codehaus.plexus.configuration.xml.XmlPlexusConfiguration;
at org.apache.maven.lifecycle.internal.BuilderCommon.handleBuildError(BuilderCommon.java:128)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:95)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:316)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:153)
at org.jvnet.hudson.maven3.launcher.Maven3Launcher.main(Maven3Launcher.java:78)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchStandard(Launcher.java:329)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:239)
at org.jvnet.hudson.maven3.agent.Maven3Main.launch(Maven3Main.java:148)
at hudson.maven.Maven3Builder.call(Maven3Builder.java:119)
at hudson.maven.Maven3Builder.call(Maven3Builder.java:69)
at hudson.remoting.UserRequest.perform(UserRequest.java:114)
at hudson.remoting.UserRequest.perform(UserRequest.java:48)
at hudson.remoting.Request$2.run(Request.java:270)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.ClassCastException: [Lorg.codehaus.plexus.configuration.PlexusConfiguration; cannot be cast to [Lorg.codehaus.plexus.configuration.xml.XmlPlexusConfiguration;
at hudson.plugins.cobertura.MavenCoberturaPublisher.preExecute(MavenCoberturaPublisher.java:50)
at hudson.maven.Maven3Builder$MavenExecutionListener.reccordMojoStarted(Maven3Builder.java:463)
at hudson.maven.Maven3Builder$MavenExecutionListener.forkStarted(Maven3Builder.java:593)
at org.apache.maven.lifecycle.internal.DefaultExecutionEventCatapult.fire(DefaultExecutionEventCatapult.java:88)
at org.apache.maven.lifecycle.internal.MojoExecutor.executeForkedExecutions(MojoExecutor.java:314)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:185)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:148)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:140)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
... 24 more

Looks like a ClassLoader issue.