About Lori's Baby, I see a few possible outcomes in no particular order:
1. Baby is born and Lori Lives. There is no way for them to know for sure whether the baby is infected without advanced lab equipment. No new knowledge is gained, really, but everyone (mostly) is happy about this.
2. Baby is born and Lori dies in birth. Lori turns into a zombie, perhaps even during the pregnancy. Could be a pretty intense episode to have to deliver a baby from a zombie. No new knowledge is gained though.
3. Baby dies in the womb or during child birth. Turns into zombie and possibly kills Lori (if shes still alive) from the inside (this would be difficult seeing as how the baby will have no teeth, but I'm sure with enough zombie persistence it would eventually kill her) Gained Knowledge: We now know that there is probably no hope for a world without zombies because newborns/fetus are infected too.
4. Baby dies in the womb or during child birth. Does not
turn. This could be very important because even if the baby is dead, it could show that newborns might not be infected. Ironically, the death of the baby could provide hope for humanity of a world without zombies.