From a DarkUFO poster who has seen the AOL Cast Interviews
I've watched the whole sequence of the interviews on AOL and I have to say there are some very interesting bits and pieces.
1) Sun was told by a producer that the kid is probably not Jin's, but Jin was told by another producer that it is his :).
2) The Desmond flashback will be like nothing that has been done before, and it will blow the audience away.
3) Locke got in his wheelchair because of a "banana peel".
4) There is a Sayid episode that "will answer questions about the Others and the DHARMA initiative, and the relationship between those two groups, which might involve the guy with the eyepatch".
5) Jack will be brought back to Othersville -- won't stay in Alcatraz.
6) There will eventually be an explanation about what happened to Desmond, and the sky turning purple. He'll have a "significant prophecy" for one of the characters.
Source: Various Cast Interviews