Podcast interview with Michael Emerson reveals a few spoilers:
When asked about upcoming deaths, Michael only mentioned one by name. He said "I'm worried about Charlie". He then stopped to think about what has already aired and then said "nevermind". When describing Charlie's character he said "he makes mistakes".
When speaking of the Others, he indicates that he believes there is a reason why they seem to have superstrength. He was specifically told when climbing the cliff with Sawyer in EMFH that it was "very easy for Ben, and very tough for Josh."
He says the question of Ben and Alex's relationship will soon be answered.
He says there may be a reason why Ben when to Lostie beach alone. He may have a certain quality that made him uniquely suited for the mission.
He says the Others are possibly nearly like normal humans but have one thing different. One should consider why they seem stronger (Juliet knocking out Jack, Ben beating on Sawyer, Goodwin, etc.) and why they don't seem to want to leave the island when it appears they can.
Lastly, he says Ben being out of commission from the surgery may create a vaccuum of power that some "frightening characters" we haven't met yet may try to step into.
Pikki weren't very smoothly introduced but they may become more important.
The Others we know do not work for Dharma or Hanso.
Ben really has lived on the island his whole life.
We will see the Others have contact with the outside world.
There is more than one group of Others that the Others are aware of but are not a breakaway group of theirs.