This week's episode gave me some fodder for my undying Widmore is the Secret Founder of DHARMA theory:
1. He used Pylons just like DHARMA did to keep smokey out. The other-others use Ash.
2. He had access to surveys that DHARMA (Jin) conducted in the 70s.
Back to the Ash/Pylons thing... it fits in with my idea that there's often conflicts between Science and Faith on Jacob's team. When Ben assumed command of the Others, he represented "Faith." "Faith that the island would fulfill its role." Widmore, presumably, represented "Science." I still think that Ben cast him off the island when he found out that Widmore had secretly brought DHARMA to the island. He brought them to the island to study it, so that they could "cause" the island to fulfill its role. So they could understand and then recreate the phenomena of the island in case it ever "went on the blink."
And the function of the island? More and more it seems that it is to contain the smoke monster?
Also, consider The Book of Revelations in the Bible, chapter 20: 1-3 http://www.awitness.org/biblehtm/re/re20.htm
20:1 I saw an angel coming down out of heaven, having the key of the abyss and a great chain in his hand.
20:2 He seized the dragon, the old serpent, which is the devil and Satan, who deceives the whole inhabited earth, and bound him for a thousand years,
20:3 and cast him into the abyss, and shut it, and sealed it over him, that he should deceive the nations no more, until the thousand years were finished. After this, he must be freed for a short time.
It's possible that the island is the prison of that old serpent, the devil. And that he is either preparing to be loosed for a season, or he is going to be bound again- to repeat the cycle in another 1000 years.