It seems like every time you try to run these two together, you should spend some time configuring them.
After some googling and testing, here’s what my pom.xml looks like:

<repositories>
	...
	<repository>
		<id>prime-repo</id>
		<name>PrimeFaces Maven Repository</name>
		<url>http://repository.primefaces.org</url>
		<layout>default</layout>
	</repository>
	<repository>
		<id>sourceforge</id>
		<name>sourceforge</name>
		<url>https://oss.sonatype.org/content/repositories/sourceforge-releases/</url>
	</repository>
	<repository>
		<id>jboss-public-repository</id>
		<name>JBoss Repository</name>
		<url>https://repository.jboss.org/nexus/content/groups/public</url>
		<releases>
			<updatePolicy>never</updatePolicy>
		</releases>
	</repository>
</repositories>

<dependencies>
	<dependency>
		<groupId>com.sun.faces</groupId>
		<artifactId>jsf-api</artifactId>
		<version>2.1.0-b03</version>
		<scope>compile</scope>
	</dependency>
	<dependency>
		<groupId>com.sun.faces</groupId>
		<artifactId>jsf-impl</artifactId>
		<version>2.1.0-b03</version>
		<scope>compile</scope>
	</dependency>
	<dependency>
		<groupId>javax.servlet</groupId>
		<artifactId>servlet-api</artifactId>
		<version>2.5</version>
	</dependency>
	<dependency>
		<groupId>org.primefaces</groupId>
		<artifactId>primefaces</artifactId>
		<version>3.5</version>
	</dependency>
	<dependency>
		<groupId>org.richfaces.ui</groupId>
		<artifactId>richfaces-components-ui</artifactId>
		<version>4.3.0.Final</version>
	</dependency>
	<dependency>
		<groupId>org.richfaces.core</groupId>
		<artifactId>richfaces-core-api</artifactId>
		<version>4.3.0.Final</version>
	</dependency>
	<dependency>
		<groupId>org.richfaces.core</groupId>
		<artifactId>richfaces-core-impl</artifactId>
		<version>4.3.0.Final</version>
	</dependency>
	<dependency>
		<groupId>org.richfaces.api</groupId>
		<artifactId>richfaces-components-api</artifactId>
		<version>4.3.0.Final</version>
		<type>pom.lastUpdated</type>
	</dependency>
</dependencies>

And then make sure you have this <h:outputScript> in your <h:head> (It is in the facelets template file in my case):

<h:outputScript library="javax.faces" name="jsf.js" target="head"/>

That did it for me, let me know if it didn’t for you.

This solution was tested using: JSF v2.1.0-b03, PrimeFaces v3.5 and RichFaces v4.3.0.Final