Mojarra 2.3.0 will be the JSF 2.3 Reference Implementation, which is targeted for inclusion in Java EE 8. So it is clearly 'work in progress' as the JSF 2.3 specification itself (JSR 372) is currently being worked-on.
It should also be mentioned the Arjan Tijms has been recently granted committer rights on Mojarra. There is no need to introduce Arjan as he is well known in the JSF eco-system, e.g. he is one of the 'faces' behind OmniFaces. In this interview, Arajn clarifies the relation between JSF, OmniFaces and PrimeFaces. In addition to JSF, Arjan is also a very active (and vocal) EG member of the 'Java EE Security' JSR (JSR 375). “Proficiat Arjan”; it's great to see community members being so involved!