When the "lawyers" showed up at Kate's door asking for blood samples, I immediately thought Ben was behind it. He knows she would run and this is probably his way of orchestrating her return to the island.
I'm not totally convinced Sun doesn't blame Kate for Jin's death. Something about the way she was acting was definitely off. She may blame multiple people (Kate, Jack, Ben) and plans to get revenge on them all. Or maybe she is just detached now from any feeling and I'm reading too much into it.
If Sun has to be part of the group to go back, I wonder if she will be able to take her daughter. Even though Desmond is not an O6, is he required back on the island as well? And what if Penny goes with him this time? What about the pilot - does he have to go back too? If more than the O6 go back, will that keep the time jumping from being fixed? Hmm, lots to think about.
As always with Lost, the little details escape me but every now and then I notice stuff . I try not to get upset about what I miss and just enjoy the ride.
And all this time travel leads credence to people's theory that Locke may be Jacob. He may not have a body anymore since he had to "die."
And dangit, is Claire dead or not?!