HI,
Trying to download the latest G V2.1.2 from my Eclipse workspace. These are the steps I follow

1) Downloaded the latest GEP source.
2) Build was successful.
3) Started another instance of Eclipse from my Eclipse workspace.
4) Adding a server runtime.
5) Clicked on Download and Install.
6) Got the license panel. Later I hit the following error.

org.eclipse.wst.server.core SEVERE    07/08/08 17:57.57.531 Error installing feature
org.eclipse.core.runtime.CoreException: Could not download and install update feature.
    at org.eclipse.wst.server.core.internal.InstallableRuntime.install(InstallableRuntime.java:260)
    at org.apache.geronimo.st.ui.internal.GeronimoRuntimeWizardFragment$1$2.run(GeronimoRuntimeWizardFragment.java:247)
    at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:121)
org.apache.geronimo.st.ui:  Error installing runtime
org.eclipse.core.runtime.CoreException: Error occurred installing server: Could not download and install update feature.
    at org.eclipse.wst.server.core.internal.InstallableRuntime.install(InstallableRuntime.java:271)
    at org.apache.geronimo.st.ui.internal.GeronimoRuntimeWizardFragment$1$2.run(GeronimoRuntimeWizardFragment.java:247)
    at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:121)
Caused by: org.eclipse.core.runtime.CoreException: Could not download and install update feature.
    at org.eclipse.wst.server.core.internal.InstallableRuntime.install(InstallableRuntime.java:260)
    ... 2 more

In my eclipse workspace .metadata/.log I have the followng error

!ENTRY org.eclipse.update.configurator 4 0 2008-08-07 17:56:45.406
!MESSAGE Unable to find feature.xml in directory: C:\gep_new\trunk\features\.svn

!ENTRY org.eclipse.update.configurator 4 0 2008-08-07 17:56:45.406
!MESSAGE Unable to find feature.xml in directory: C:\gep_new\trunk\features\bigG.gif

!ENTRY org.eclipse.update.configurator 4 0 2008-08-07 17:56:45.406
!MESSAGE Unable to find feature.xml in directory: C:\gep_new\trunk\features\pom.xml

!ENTRY org.eclipse.update.configurator 4 0 2008-08-07 17:56:45.421
!MESSAGE Unable to find feature.xml in directory: C:\gep_new\trunk\features\Thumbs.db

I also modified C:\gep_new\trunk\plugins\org.apache.geronimo.st.v21.core\plugin.xml as follows. This is the new staging site created by Tim.

<extension point="org.eclipse.wst.server.core.installableRuntimes">
        <installableRuntime id="org.apache.geronimo.runtime.tomcat.21"
            featureVersion="2.1.2"
            featureId="org.apache.geronimo.server.tomcat.v21.feature"
            featureSite="http://people.apache.org/~mcconne/releases/2.1.2/RC1/staging_site/eclipse/updates/"
            path="geronimo-tomcat6-javaee5-2.1.2.zip">
        </installableRuntime>
        <installableRuntime id="org.apache.geronimo.runtime.jetty.21"
            featureVersion="2.1.2"
            featureId="org.apache.geronimo.server.jetty.v21.feature"
            featureSite="http://people.apache.org/~mcconne/releases/2.1.2/RC1/staging_site/eclipse/updates/"
            path="geronimo-jetty6-javaee5-2.1.2.zip">
        </installableRuntime>
    </extension>


 I also created a new remote site in my Eclipse workspace which is same as the staging site(http://people.apache.org/~mcconne/releases/2.1.2/RC1/staging_site/eclipse/updates/)

I am using Eclipse Ganymede however I hit the same error when I use Europa. I am using sun java 1.5.0_13

This error is somehow stopping me to work on GERONIMODEVTOOLS-325 wherein I need to recreate a error as pointed by Tim
Please help!!!

Thanks
Ashish