1) Fans are referring to the people on the ship as "The Freighties"...so, we have Losties (the original cast from Season 1 who were in the cabin), the Tailies (survivors from the tail section), The Others, and now The Freighties.
Source [1]

****Warning**** SKIP #2 IF YOU DON'T WANT TO KNOW ABOUT FUTURE EPISODES*************************
2) There is a Michael-centric episode coming up in March...so it seems at this point that our speculation that Ben's "man" on the ship is Michael could be correct. Libby will also appear in this episode - hopefully to give some explanation as to how she ended up in the mental hospital with Hurley.
Source [2]
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3) One theory suggests that all of the survivors have been on the island before, but they can't put the pieces together. Evidence: Locke believes it is his destiny to be on the island, he saw Boone's death before it happened, he knew where the hatch was, and he knew where the prop plane with Eko's brother crashed. Other hints at this theory: "They have all had some sort of vision of past or future while on the island, whether it be Charlie’s visions of saving Aaron, Jacks’ visions of his father, Eko’s of his brother, Claire’s visions of someone wanting to take her baby, Kate seeing the horse and hearing her father’s voice, Sawyer hearing the whispers saying, 'It will come back around,' -- you get the point." Source [3].

Now, this is where this theory gets really good....Obviously, you can click on the source link and read the whole thing yourself, but for the sake of being pithy, I'll paraphrase:

The island is the key to the time travel. Entering the atmosphere at different bearings is what causes the mind to jump into different time periods, and Daniel is the person who has unlocked that mystery....also (and this is my thought here), this could be the reason we see him crying when he sees the footage of the Oceanic plane crash - he hasn't been there yet, but his mind has already experienced the events and is causing him to have an emotional response to the footage. To me, that denotes that things don't turn out so great.

More evidence:

"Lenny Toomey - from passing near the island’s atmosphere.

Hurley -He mentions to Sayid that they can hear music from “another time.”

Desmond

Radinsky - killed himself because he had no constant?

Jack..in the future - talking about his father being alive? Is he having flashes? When he tells Kate they have to go back - Does he mean back to the island? Or back in time? Hmm

Sawyer even said something is season one that has always stuck with me -To Kate: I made this wish four years ago.

The whispers and hallucinations are a result of traveling into and being trapped in the doorway between worlds (which is the island). This is why they envision people and things that are not there -voices that are not real -they are all things that the islands atmosphere “receives” from other times because it is traveling between. It is a tesseract."

This theory is VERY good, but lengthy, so I really suggest that you all read it for yourselves so we can discuss...it gets into Danielle's crew members - remember, they had the sickness?; Claire's psychic seeing events from an alternate timeline, etc.

Also, it includes a line I'd forgotten about where Ben tells Locke that the island is hidden "even from God."
Source [4]