Have you noticed how all of the characters are resolving their problems in timeline x? Kate is free, Claire could be keeping her baby, Locke is accepting his disability, Jack is getting a better relationship with his father kind of... They're all resolving their personal problems they've had all along. Next episode should be Sun and Jin centric (based on the fact that so far season 6 is paralleling season 1) and I bet they'll start to work out their marriage problems. The writers have something up their sleeve with this.
By the way, who's idea was it to call it timeline X? That's terribly unoriginal. I think it should be called the UnLost Timeline.