Product Version: NetBeans IDE Dev (Build 200909081533)
Java: 1.6.0_14; Java HotSpot(TM) Client VM 14.0-b16
System: Linux version 2.6.24-24-generic running on i386; UTF-8; cs_CZ (nb)
Userdir: /home/david/.netbeans/dev

GF running. On web project I hit "Run", the following was printed to the output:
init:
deps-module-jar:
deps-ear-jar:
deps-jar:
Created dir: /home/david/NetBeansProjects/WebTest1/build/web/WEB-INF/classes/META-INF
Copying 1 file to /home/david/NetBeansProjects/WebTest1/build/web/WEB-INF/classes/META-INF
library-inclusion-in-archive:
Copying 1 file to /home/david/NetBeansProjects/WebTest1/build/web/WEB-INF/lib
Copying 1 file to /home/david/NetBeansProjects/WebTest1/build/web/WEB-INF/lib
library-inclusion-in-manifest:
compile:
compile-jsps:
/home/david/NetBeansProjects/WebTest1/nbproject/build-impl.xml:568: 
Deployment error:
null
See the server log for details.
        at org.netbeans.modules.j2ee.deployment.devmodules.api.Deployment.deploy(Deployment.java:227)
        at org.netbeans.modules.j2ee.deployment.devmodules.api.Deployment.deploy(Deployment.java:135)
        at org.netbeans.modules.j2ee.ant.Deploy.execute(Deploy.java:103)
        at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288)
        at sun.reflect.GeneratedMethodAccessor140.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:106)
        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:1337)
        at org.apache.tools.ant.Project.executeTarget(Project.java:1306)
        at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
        at org.apache.tools.ant.Project.executeTargets(Project.java:1189)
        at org.apache.tools.ant.module.bridge.impl.BridgeImpl.run(BridgeImpl.java:278)
        at org.apache.tools.ant.module.run.TargetExecutor.run(TargetExecutor.java:497)
        at org.netbeans.core.execution.RunClassThread.run(RunClassThread.java:151)
Caused by: java.lang.NullPointerException
        at org.netbeans.modules.j2ee.deployment.impl.ServerFileDistributor.distribute(ServerFileDistributor.java:147)
        at org.netbeans.modules.j2ee.deployment.impl.TargetServer.distributeChanges(TargetServer.java:231)
        at org.netbeans.modules.j2ee.deployment.impl.TargetServer.deploy(TargetServer.java:637)
        at org.netbeans.modules.j2ee.deployment.devmodules.api.Deployment.deploy(Deployment.java:192)
        ... 17 more
BUILD FAILED (total time: 0 seconds)

Bottom of the server log:

INFO: DOL Loading time392
INFO: Started bundle org.glassfish.security.websecurity [82]
INFO: Started bundle org.glassfish.orb.iiop [110]
INFO: Initializing Mojarra 2.0.0 (RC b17) for context '/WebTest1'
INFO: Loading application WebTest1 at /WebTest1
INFO: Deployment of WebTest1 done is 3 140 ms
INFO: Total number of available updates : 0
INFO: Started bundle org.glassfish.admin.cli [17]
INFO: Started bundle org.glassfish.connectors.admin [183]
INFO: Started bundle org.glassfish.jdbc.admin [113]