Dúvida no Ex. 1 da Aula 2 - Cadastro de participante | Java: Laboratório web de práticas e tecnologias

Estou com problema na hora de fazer o binding, quando eu submeto o formulário, os campos estão nulos.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
      xmlns:ui="http://java.sun.com/jsf/facelets"
      xmlns:f="http://java.sun.com/jsf/core"
      xmlns:h="http://java.sun.com/jsf/html" 
      xmlns:p="http://primefaces.org/ui">

    <h:head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
        <title>Bem-vindo</title>
    </h:head>

    <h:body>
        <h:form>
            <p:panelGrid columns="1">
                <p:outputLabel value="Nome: " />
                <p:inputText value="#{usuarioBean.usuario.name}" />

                <p:outputLabel value="Usuário: " />
                <p:inputText value="#{usuarioBean.usuario.user}" />

                <p:outputLabel value="Senha: " />
                <p:password value="#{usuarioBean.usuario.pass}"/>

                <p:commandButton value="Vamos lá!" action="#{usuarioBean.ok}" />            
            </p:panelGrid>
        </h:form>        
    </h:body>

</html>

    @Named
@RequestScoped
public class UsuarioBean {

    private Usuario usuario = new Usuario();

    public Usuario getUsuario(){
        return this.usuario;
    }

    public void ok(){
        System.out.println("Nome: " + usuario.getName());
        System.out.println("Usuario: " + usuario.getUser());
        System.out.println("Senha: " + usuario.getPass());
    }

}

@Entity
public class Usuario {

    @Id @GeneratedValue
    private long id;

    private String name;
    private String user;
    private String pass;


    public Usuario(){}

    public long getId() {
        return id;
    }
    public String getName() {
        return name;
    }
    public String getUser() {
        return user;
    }
    public String getPass() {
        return pass;
    }


    public void setId(long id) {
        this.id = id;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setUser(String user) {
        this.user = user;
    }

    public void setPass(String pass) {
        this.pass = pass;
    }

}