I'll admit: Immediately upon hearing the explanation about the whispers, I thought that it was a bit of a cop-out. I feel like it was more a matter of the relative ease in which Hurley solved the mystery that made the unveiling so anticlimatic. The carefree nature of Hurley's discovery and his 'not-so-surprised' reaction to Michael's confirmation of the whispers made the audience also feel like it was not an important revelation. I think that the mystery was turned over in such a way that made the audience feel like it was an obvious reveal.
I feel like the whispers were never entirely thought out by the producers, but were moreso introduced to add a mysterious aura to the show with the intention of writing in an explanation later on. I think they really shot themselves in the foot by making the whispers appear like they were directly related to the Others in so many situations. I think the one situation where this really rang apparent was in "The Other Woman" when Harper appeared to the backdrop of whispers, and also disappeared to them. The only situations where it seemed like the whispers were unrelated was Season 2 when Shannon died, and a whisper said, "I'll see you soon, sis." This was clearly Boone, and doesn't appear to be related to the Others.
Also, if the whispers are the voices of those who died on the island, and their souls are stuck in some sort of 'purgatory,' what was the meaning behind that voice that Sawyer heard in the jungle that said something close to, "It will all come back around," which were the final words muttered by the Australian food vendor before his was mistakenly shot by Sawyer. I feel like this example completely contradicts the explanation that we got last night, which makes me think that the producers introduced the whispers intially without entirely knowing how they would resolve it. What does everyone else think?