I have a theory here, but I'm not enitrely sure about whether it works entirely.
In 'The Other Woman', Harper says to Juliet 'Of course he does, you look just like her'. And I was thinking, looks like who?
And then they went back to the 70's Island, and then in 'Namaste', Ben is there at the end with Sayid. So I figure that in a future episode, Ben will look to Juliet as a guardian within the Initiative because of his father's negligence. And then something happens, she goes, he vaguely remembers her face.
Then he grows up and hires her again in 'Not in Portland'/'One of Us'. And he hires her not only because of her fertility expertise, but because of her resembalnce to the woman who looked after him when he was younger - the woman who actually is Juliet Burke.
Seems plausible to me but see what you think ^_^