SO since last night there has mostly been widespread complaining about "What Kate Did". While certainly not going on the list of best episodes of all time, there were still a lot of questions raised. These ones are about time travel, which has not been talked about a great deal since LA X premiered.
First, Claire is back! I personally am super excited about this, and secretly hope that somewhere Charlie is with her. BUT this does raise a question about time travel. It was certainly implied that it was not Rousseau setting those new traps ("she's been dead for years") and made to seem like it was Claire. However, these traps are appearing in the modern timeline. Thus, logically it seems that Claire did not travel back with the Losties through time. I think that this could show a special status and a clue to what is going on with her character (like that she is sick or dead or taking on the role of Rousseau)
Second, One thing that I have not seen addressed is HOW the Losties got back to 2007( or 8 or whenever the island present is). Before LA X premiered there were a lot of theories going around that Eloise or someone else managed to turn the FDW and skip the island. I still think that this is a valid theory. If in the island timeline no bomb ever went off then how did they get "blown" back to the future? I don't know that this is vital to the final mythology, but it could explain in BOTH realities how Eloise was able to get off the island and raise Daniel.
Third, I LOVED seeing Dr. Ethan Goodspeed. I don't know if this counts as time travel related. But I think this confirmed 1)that in the alternate reality Ethan, Amy,Miles, Charlotte, and all the other DI women and children and non-essential personal survived and lived off-island lives. and 2) That "Rom" as his surname had something to do with his transformation from DI to an Other.
Finally, Does anyone have an idea what happened to post-shot Ben Linus in the flash-sideways? Was he on the island and now dead when the bomb (presumably) went off?