Eclipse 3.7 (Indigo) に Google App Engine Plugin を追加する

GAE のプラグインを Eclipse IDE for Java Developers や Eclipse Classic 3.7 にインストールしようとすると下のようなエラーが出ます。
必ず Eclipse IDE for Java EE Developers を使うようにしましょう。

ちなみに Install New Software から入力する URL は
http://dl.google.com/eclipse/plugin/3.7
です。

Cannot complete the install because one or more required items could not be found.
  Software being installed: Google App Engine Java SDK 1.5.1 1.5.1.r37v201106211634 (com.google.appengine.eclipse.sdkbundle.e37.feature.feature.group 1.5.1.r37v201106211634)
  Missing requirement: Google App Engine Plugin 2.3.2.r37v201106211634 (com.google.appengine.eclipse.core 2.3.2.r37v201106211634) requires 'bundle org.eclipse.wst.xml.core 0.0.0' but it could not be found
  Cannot satisfy dependency:
    From: Google App Engine SDK 1.5.1.r37v201106211634 (com.google.appengine.eclipse.sdkbundle 1.5.1.r37v201106211634)
    To: bundle com.google.appengine.eclipse.core 0.0.0
  Cannot satisfy dependency:
    From: Google App Engine Java SDK 1.5.1 1.5.1.r37v201106211634 (com.google.appengine.eclipse.sdkbundle.e37.feature.feature.group 1.5.1.r37v201106211634)
    To: com.google.appengine.eclipse.sdkbundle [1.5.1.r37v201106211634]

Cannot complete the install because one or more required items could not be found.
  Software being installed: Google Plugin for Eclipse 3.7 2.3.2.r37v201106211634 (com.google.gdt.eclipse.suite.e37.feature.feature.group 2.3.2.r37v201106211634)
  Missing requirement: Google Plugin for Eclipse 3.7 2.3.2.r37v201106211634 (com.google.gdt.eclipse.suite.e37.feature.feature.group 2.3.2.r37v201106211634) requires 'org.eclipse.wst.common.project.facet.core 0.0.0' but it could not be found