I've already replied to the cross-post.
You need to bootstrap the AVM based WCM, same as for Alfresco 2 and 3.
The wcm bootstrap file is in the alfresco-community-AVM-4.0a.zip file on the community download page, just stick it in your shared/classes/alfresco/extension folder and reboot.
And make sure you are using lucene as the search engine to use AVM on alfresco 4.