Are you kidding? What big question has been answered? Any thing that you learn about just brings up more questions.
Stuff that hasn't been answered:
1) Walt and all of his business. Was the polar bear his creation? Sawyer was in a bear cage, but was that really where the bear came from? Or was a manifestation from the comic book like the bird in his flashback?
2) 3 Toed statue, that was pretty significant, and forgotten about.
3) The black fog monster, still don't know what it is.
4) Healing power of the island?
5) The button? The number code? Any resolution there?
6) The interlinking of all the main characters, they are all a few degrees from knowing each other.
7) The Dharma Initiative... what why when?
Its been a while, but Im pretty sure Ethan was like, super human. What became of that?
And the new stuff, really, how many hours would you spend with cooky physicist and creepy redhead without beating out of them what their true purpose in coming to the island was? Its been stretched out to like 6 episodes!
hehe, all of the known facts and highly intelligent theories for ALL of those questions was on the deleted site.

1) Dharma definitely was doing animal testing and the like on the island. As we have seen in this season, someone on the island was tinkering with time travel AND teleportation ( Polar Bear skelton in the sahara, Ben in the Sahara)
With Walt, who knows. I think the whole Walt thing was never planned out for a long run, but you'll never hear the producers admit it.
2) The statue will most likely be explained next season. The way they are expanding on the ageless Richard Mittelos, I think we will be finding out about the original inhabitants sooner than later. (I think that guy only has 3 toes if you must know)
3) There is alot of info on the black smoke monster. My personal opinion that most share - smokie IS jacob. The crazies have gleaned from high res screens and such that smokie has 'flashes' within it when it meets someone. These flashes on closer inspection are flashes from said persons life. So basically, smokie is 'downloading' the person's memories. Producers have also confirmed that smokie does in fact take the shape of people/animals and such - as in the case of Eko's brother, Yemi. And when Ben called the monster a few episodes ago, high res screens showed that when it came over the wall it had a defined animalistic face.
4) who knows. Odds are the island is alive or something. Some people cite the magnetic properties of the island.
5) I doubt you will ever get an answer to the button or the number thing. The numbers haven't been mentioned since, and they dropped the hatch subject like a bad habit when it imploded. Don't forget the purple sky, and others. These are more from the 2nd season though, not the 1st season.
6) Not all of the people are important to the island. They just happened to be there. Don't forget all the kids and passengers that the others captured. They never explained those, and they even had that odd scene last season when they were all standing outside Sawyers cage.
7)I think the Dharma initiative will be tied to Mr. Widmore somehow. What I am more interested in is WTF happend to bringing the Hanso foundation into the actual show. Was that whole immersive game thing pointless or what?
8)Yeah, and that still irritates me. What irritates me more though is the fact that Juliet was a mousy nobody in real life, she has only been on the island 3 years, there has been NO indication of special training for her, and SHE has superpowers and is a fighting/arms expert.