Technically, I don't think Kate was revealed as an Oceanic Six survivor until the last episode. She was in Jack's Flash-Forward last season but that was before we knew about the Oceanic Six.
I'm wondering how they are going to reconcile the whole Aaron thing - if he was considered "Kate's" baby she'd have to be nearly as pregnant as Claire was at the time of the Oceanic 815. Surely someone in the law enforcement would have known that she was 8 months pregnant when the Marshall was bringing her back the US. I just don't see how that adds up.
Before the end of the last epsiode - I was convinced that the Oceanic Six were: Jack, Kate, Sayid, Hurley, Locke, and Sawyer. Now, I'm doubting both Locke and Sawyer.
BTW, I'm just catching up on this thread becuase I hadn't watched most of the new episodes this season until last night - remind me, who is Christian?