Excellent.
It's coming together at last! This whole sideways universe is making more sense- it's not supposed to be that way. Well, duh, but now the Losties are really seeing it.
Why did I just know it would be Desmond and Charlie who really put it together first?
My original theory was that the island folk had to die to get to the alt/reality. Now I think they have to die in the alt/reality to get back to the island reality, then have the big MiB showdown with the remaining candidates
The alt/reality was caused by the bomb. It is 'wrong' and our characters are figuring that out with 'bleedthrogh' that Charlie saw when he almost died, Desmond saw when he almost drowned (and in the MRI) and Daniel knows too, not to mention Eloise.
It all coming together! I think we'll see more characters in the alt/reality figure it out too (based on some spoilers I read)