Wow! Now we get to flash into the future instead of the past? I'm very excited about the fourth season. This show is so full of loose ends though... a lot of big questions were answered this season, but there is still plenty of stuff (some of it has only been mentioned briefly) that absolutely demands answers. What questions do you want answered? Here's just a few of the things I'm wondering about
1. Jacob's list ("the list").
So Jacob, the leader of the Others, has a list of people who are "good" and able to understand the Others (or their purpose). The crash survivors who were on the list were kidnapped (apparently everyone on the list was in the tail section). I can't recall all of the dialog about the list, so I don't remember if it was only a list of crash survivors or if there's a larger list of good people (which would probably include all of the Others). Is Jacob actually Santa Claus? It's only been talked about a handful of times but has a huge impact on the actions of the Others (and thus the plot in general), so we should be hearing more about it in the future when we really learn more about the Others and Jacob. Also -- what has become of the good people who they kidnapped from the tail section?
I've read a theory that Jacob is actually Jack (from the future). It makes sense in a weird sort of way, and the framework for making this possible is already basically in place in the series. Jack of the future realizes that it was wrong for him to leave the island and wants to find a way back. Even more than that, he would probably want to undo his big mistake of leaving the island. In the season finale Locke told Jack, "you are not supposed to do this," which I don't think is good supporting evidence because Locke's character often has strong opinions of what other characters are and aren't supposed to do, and he usually treats them as fact. What was Jacob's message to Locke though? "Help me." Also not proof, but they both fit. Now, how does future-Jack come back and become Jacob? He doesn't! We have already seen that Desmond receives flashes of future events. What if Ben's (and eventually Locke's) communication with Jacob works in a similar manner? This would certainly explain why Jacob isn't always visible, and why Ben and Locke see him seperately and not together. Maybe they're both receiving flashes of future-Jack. Or maybe they're receiving flashes from future-Jack. Also, the brief image of Jacob we saw did bear some resemblance to Jack's father, I think. Is this what Jack as an old man would look like?
2. resurrection and fast healing
Jack's father died but his coffin is empty. Their plane crashed on the island, but it was also found with no survivors (or now that we've learned that Naomi was NOT who she said she was, and is one of the "bad guys" as the Others refer to them, can we really believe her about this -- or was this possibly confirmed by Penny when Charlie got ahold of her? I can't remember.) Mikhail just refuses to die. How will this be explained? When future-Jack refers to seeing if he's more drunk than his father, does he possibly mean that his father is literally upstairs, alive and well? I doubt it, but I'm still curious where his body went.
3. the giant statue with four toes
Sayid, Jin, ad Sun saw this thing at the end of season two. It was a real Planet of the Apes moment. The Others don't have four toes do they? And in any case they recruit members from other groups/physical locations (Ben, Juliet). They don't seem like the type of people to create huge statues with four toes. Who was on the island before the Others?

4. whispering in the jungle
This may be related to the Others, or the smoke monster... or perhaps another group of people (perhaps they belong to never seen, sometimes heard original inhabitants of the island who happen to have four toes).
Now I'm tired of writing whee!