I switched the openshift-profile in the pom from

<artifactId>maven-war-plugin</artifactId>

<artifactId>maven-ear-plugin</artifactId>

I then republished the project and now (was not the case before) spotted the following in the server log:

2012/06/26 10:49:40,372 INFO  [org.jboss.as.server.deployment] (MSC service thread 1-3) JBAS015876: Starting deployment of "multi.ear"
...
012/06/26 10:49:41,561 INFO  [org.jboss.as.server.deployment] (MSC service thread 1-2) JBAS015876: Starting deployment of "multi-ejb-0.0.1-SNAPSHOT.jar"
2012/06/26 10:49:41,561 INFO  [org.jboss.as.server.deployment] (MSC service thread 1-2) JBAS015876: Starting deployment of "multi-web-0.0.1-SNAPSHOT.war"

If you now tell the server adapter to show in the browser you'd be showed / which is returning a blank page.
The correct url for your ear may be spotted in the server log:

2012/06/26 10:49:56,278 INFO  [javax.enterprise.resource.webcontainer.jsf.config] (MSC service thread 1-1) Initializing Mojarra 2.1.7-jbossorg-2 (20120412-0335) for context '/multi-web'

If you access /multi-web you'd get the expected web-application with the content.

Unable to render embedded object: File (multi-web.png) not found.

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