Ok I usually don't post theories because most of the time someone else has already thought of it before, but I've looked and I have not found anything else on this theory I've made.
Let's start with where the numbers originally came from; the Valenzetti equation. Now I know the Valenzetti equation story hasn't really been formally shown on the actually show it had a major focus in the ARG and I'm pretty sure the writers have confirmed the Valenzetti equation to be cannon. It will most likely be introduced in the next season. If your not familiar with the Valenzetti equation please watch  before you go on. It is revealed in this video that the DHARMA initiatives goal is to change the core numerical values of the equation in order to change the fate of humanity. Now I don't know exactly what will happen when one of these numbers are changed or how they will be changed (the hydrogen bomb reset possibly?) but I'm fairly confident I know what the number will be changed to, or should be changed to atleast.
When the numbers were first introduced to show and started to become very prominent in the show I of course like most people I'm sure tried to find a pattern in the numbers. At first it didn't seem like there was any type of pattern at all and they are in fact just random numbers. Then I thought I had found a pattern, but it was one number off so I just forgot about it. Anyways here is the original pattern I had:
So the numbers start with 4 then go to 8. 8 is double 4, 16 the double of 8 is also in the numbers. However the number 15 breaks up that pattern. So I tried to figure out how it goes from 8 to 15. I just went the simple way first, 8+7=15. Just so happens to be if you add 7 to 16 you also get the next number in the equation-23. So if you stop the numbers at 23 there is a bit of a pattern.
So the pattern looks something like this; in order to find the values in 'A B C D E'(you would need to know the value of A) you would take value A add 7 to get value B and double value A to get value C. Then to get Value of D you would add 7 to C and the value of E would be double C. So for example if the Value of A was 9 the numbers would look like : 9 16 18 25 36.
I realize in the real equation the numbers go from 4 to 8 instead of 4 to 11, but this most likely because 11 is greater than 4's double 8 and the numbers go from least to greatest so 11 would have to be skipped.
Now the most important part. If you follow my pattern the numbers should be 4 8 15 16 23 32 instead of 42. So at the time I just thought the pattern didn't mean anything and was either a coincidence or the writers purposely made the numbers close to a pattern to tease people. During a rewatch of LOST I started recently I started to notice the number 32 showing up a lot. So that combined with the possibility of a change in the numbers made me think again about my pattern. This is just a joke news report on LOST done by The Onion, but Damon and Carlton joined in on it, listen to what Damon says about the Valenzetti equation. 
Heres some examples of 32 showing up in LOST:
When the losties first go inside the hatch and have to push the button for the first time, they put in the numbers 4 8 15 16 23 32 because Desmond had left and they were not sure about the last number. Jack comes back and then corrects them on it.
325 is the coordinates Ben gives Michael to follow in order to get off the island.
3.2 million dollars is what Miles ask Ben for. That is also double what Widmore was paying him (1.6 million)
While Ben is waiting in line at Simon's Butcher Shop to drop Locke's body off he takes a number ticket. The camera focuses on the ticket, the number is 342. On the ticket 4 and 2 are solid while 3 is just outlined.
There were a few other connections of 32 that I can remember right now, but I will try to find them and post them again, I'll try to get some screenshots also later.
I apologize for the long read, I'm not very good at explaining things. So let me know what you think or any evidence or counter evidence you might have.
TL;DR version: The losties will change the numbers into 4 8 15 16 23 32 in order to change the destiny of humanity.