I believe Jack will not succeed in detonating JugHead's core. He will instead lose it thru the struggle of when the other Lostie's ( Sawyer, Kate and Juliet) attempt to prevent him from doing so. JugHead will then be shipped off the Island via the Dharma sub that Sawyer, Kate and Juliet were to be shipped back to the "real world". Assuming that they detour back to the Island after Kate reveals Jack's plan to Sawyer and Juliet. Then future recruits of Dharma i.e. Ilana and Bram will get ahold of the core and will bring back JugHead thru Ajira Flight 316 in the metal box to possibly attempt and detonate once and for all? I conclude this because if Jack succeeds amd What Ever Happened, Happened. Then we have not seen any type of fallout in result of the detonation on the Island's physical appereance in the present time. A bomb of that magnitude should leave evidence of no plant life or animal for sometime being in l! ight of a hydrogen bomb going off.
