I don't believe for a minute that there is a real chance of a name change. That being said IF it were to happen I can see it being spun as "new" light more clearly defining what they do.
Witness: "attestation of a fact or event." So Jehovah's Witnesses must be able to attest to a FACT or event. I think we all can agree that there isn't really any proven Bible fact or event they can truthfully attest to.
Worship: "a form of religious practice with its creed and ritual, reverence offered a divine being or an act of expressing such reverence." Now THAT would fit the JDubya's much closer. The reverence they show God, and their peculiar creeds and rituals.
Just my two cents.