My Summarised Endgame Theory by fraggdya

I have been pondering an overall theory (which im summarising somewhat here) for some time now, but have not been able to estimate how it could all end - but I think now that I can!

I have always thought the island is encased in an electromagnetic bubble which stems from the anomaly but DHARMA were able to harness and control it - With such devices as the Swan station and the frozen donkey wheel. This is further backed up by the cover of the comic book on a table in an early season showing a 'mystery island' covered in a protective dome. If the 'anomaly or source' is killed off, the island sinks. I'm not going to rule out it being improperly moved so that it phases into an underwater position rendering it uninhabitable.

I think LOST stands for Loops Of Space Time, im basing this on the writers apparent love of abbreviations and acronyms, such as Mittelos Laboratories (Mittelos=Lost Time) and also that would fit nicely given the original name of the series was floated as 'The Circle' - therefore I also think that the island sees a series of iterative loops which have never been broken:-
I think this because of various things such as desmonds flashes at the turning of the failsafe key, the time 'bleeds' (why? because i think that will be the 'lead' out of the loop where real life can continue unhindered and not influenced by Jacob, MIB, Eloise, Widmore etc etc - but also because of Jacob's comments to MIB in Ab Aeterno:-

MIB: I don't have to ask. You brought them here. Still trying to prove me wrong, aren't you?
Jacob: You are wrong.
MIB: Am I? They come. They fight. They destroy. They corrupt. It always ends the same.
Jacob: It only ends once. Anything that happens before that is just progress.

I think that MIB feels that they are stuck in a loop and he wants out in some way and thats it. He has done his 'shift' like his mother and wants out.
Jacob however is confident that eventually he will get the right 'candidate' to cause a break in the loop. When he talk about an 'end' - I do not think he means a replacement like MIB was to mother - He means finishing it all.

- I think that person is Jack.

I think that Jack will be fighting to the death with MIB come the finale but i think the only way to win, is for Jack in the ALT to somehow make Locke 'see' the time/reality 'bleed' and he can be reborn and 'take himself back' if he believes. But this may take an immense act of faith from Jack and possibly Locke.

Meanwhile Desmond kills the anomaly with his ability to resist this type of phenomenon

I believe that this will break the loop and the 'ALT' becomes the reality and the island is destroyed or improperly moved underwater as the the electromagnetic energy 'bubble' that suspends the island is destroyed.

I think MIB is Jacobs brother, pure and simple - but he was turned into the smoke monster by possibly dying in the well/interacting with the singularity/anomaly in the well (this is now known and came true)

With the island's anomaly destroyed and MIB killed or the need/motivation/ability for his evil intentions gone - the world continues in what we currently know as the 'sideways'