I don’t think that Jack is the Shepard that the candidate list refers to. I think it is Christian. But why isn’t his name crossed out?He is after all, for all intent and purposes, dead. He has work to do. For whom and why is yet to be seen. But I have an strange feeling that his entity is needed on the island for a few reason, the most obvious being Jack, Claire and Aaron. Think about the following things:
1. Jack follows his image and finds the clean water which solidifies his role as leader of the Losties.
2. He seduces Claire to MIB’s side and in the process, Claire is driven crazy by the grief of losing Aaron and that fuels her grudge against the Others further more aligning her with MIB.
3. Aaron is doomed to be ‘raised by another’ because of Claire’s abandonment.
4. Everybody assumes MIB/Smokey can appear to a person as the something that the person loves the most, then why did he appear to John Locke as Christian is Smokey really does = Christian? To start a catalyst to get the Oceanic 6 back to the island (tell my son I said hello), as Ben said if you got Jack, then you got all of them (well, almost all).
Also a quick side note:
I believe that the lighthouse is MIB’s. I just think that because the candidates names are written in black and in the cave the names are written in white, sometimes the answer really is right in front of you and you are too blind to see.