season 4 I believe is about dharma, and we will see more of the numbers (The Valenzetti Equation: http://www.lostpedia.com/wiki/The_Valenzetti_Equation ) and the 4 toed statue.
The opening scene is up on youtube. It's only 4 minutes, an only about 2 of new footage. Article on IGN Trying to link to the youtube page but it's embedding.
Boring episode with cliffhanger at the end....they need to think up a new formula.....I love Lost...but come on...get to freaking Locke already....and I still have no answer to the 4 toed collosus foot
It was actually scheduled to go on for 8 seasons. I don't know if it equated to 100 episodes, but it wasn't supposed to be 4 seasons. Maybe they've put more episodes in each season than originally expected though.