A lot of online reviewers are saying how, because Rodney and Katie were reluctant to hug, that proves that they aren't in love. (usually followed by advocating the John/Rodney ship)
I think we're forgetting who we're talking about, here. Katie Brown isn't that outgoing - they established that back in Duet, and in the same episode, the only thing that kept Rodney from being paralyzed by fear, was Cadman taking over.
We McWeir shippers surely can't be alone in knowing that Rodney has never been given to physical displays of affection.
That said, given that the pregnancy arc was originally going to focus on Rodney (at least, it was until Mrs. Luttrell herself became pregnant), I wonder if the writers were going to take the Rodney/Katie relationship in a slightly different direction.