According to an interview with Michel Nandan in Czech paper magazin Rally there is going to be a change in WRC homologation rules. Since 2014 WRC homologation is not going to be an extension of S2000 homologation but a sole WRC one. That means since 2014 we will not see any more new S2000/RRC.
Nandan also said they would use X-Trac transmission and a purpose-built "global engine". Although they have 1.6T DI stock engine they don't think it's better to use it as a basis. The main reason is expected higher reliability of the purpose-built unit. In the moment the prototypes are equipped with tuned production engine. The real WRC unit is still under development.