Desmond and Eloise are the most important people in the story by blondannas

From the moment that Jack met Desmond on the steps of the stadium and Desmond said that he would see Jack in another life, his importance was established. It was further solidified when Desmond was found to be the one who was in the shaft pushing the button at the beginning of season 2.

According to Desmond's flashback, when he and Eloise met at the jewelry store in England, his was an adventure which he was doomed to repeat many times over many lifetimes. I have always been surprised that this has not been mentioned before or treated as a main topic. Then, as in season 6, Eloise discouraged him from courting Penny, even though they are destined to be together, saying that he is not ready and he has other things to do that are more important. Desmond clearly has a major role to play in the mythology of Lost
In The Constant, Desmond is important again in a different way when Penny is his constant, and Eloise's son Daniel, by Widmore, establishes the concept of the constant. This is reiterated in season 6 again at the party when Daniel appears to Desmond, Eloise once again tells Desmond that he is not ready to have a relationship with Penny because he must work with Widmore and Desmond connects with Daniel as his constant.

Now Desmond is appearing to people in the sideways much like Jacob appeared to people before they arrived on the island. And his appearances have an effect on them, enabling them to remembering things they did not remember before. Maybe Desmond is the new Jacob. I think so. But I think that Desmond is more powerful than Jacob. He is just finding out how much.

Eloise is the only one who knows how to get to the island. She is the only one who knows where the island is at any time. We have no reason to think that she was born in 1937 for sure. That is just a date mentioned at one point. She could be as old as the island. Like Desmond, she could have lived many lives.

I think that the future of the island will rest in the hands of Desmond and Eloise. Jacob and MIB have been stewards of the island for a finite number of years or centuries. Who knows how long Eloise and Desmond have been around and what they will decide to do with everyone on the island now.