Remoting JSR170 calls requires obviously both server and client sides. The server is available for download, as JCR WebDAV Server in both http://www.apache.org/dyn/closer.cgi/jackrabbit/binaries/jackrabbit-jcr-server-1.4.1.jar and http://www.apache.org/dyn/closer.cgi/jackrabbit/binaries/jackrabbit-webapp-1.4.war. However, the client is just casually mentioned as "can be found in the Jackrabbit sandbox." This issue is to request that the SPI2DAV client code (especially a ResponseFactory that returns a JCR2SPI Repository implementation) be available for download as well.
Furthermore, please make the RepositoryFactory implements javax.naming.spi.ObjectFactory so that only configuration (vs. Java coding) is needed in order to use it. This is how org.apache.jackrabbit.rmi.client.ClientRepositoryFactory works.