this doesn't have total relevance to the new episode, only a theory i have about kate's miserable 2 weeks, but what I was thinking about during the episode was
why do the others need kids and pregnant girls? they certainly have enough men and women to procreate, and then they wouldn't have to go trough all the trouble with claire and everything, and the kid will already be "good"

anyone have any ideas?

They don't need only the children so badly. As for me, I believe Walt was captured only in order to the others get Jack, Sawyer and Kate. Somewhat like a Long Con.

Perhaps something prevents them from conceiving children on the Island. Magnetism? A side effect of the Sickness? A side effect of the CURE for the Sickness? Something else that went terribly wrong in the Old Dharma Days, maybe contributing to whatever catastrophe happened? Maybe the catastrophe itself?

Lotsa questions, few answers. LOST situation normal! :rolleyes:

But, if they were only using Walt to con Jack, Kate, and Sawyer why would they run tests on Walt as well?