L., you are a good friend.
There are a wide variety of degrees of cleft lips and palates. Like many have posted already, surgeries have come so far. It won't be long before their baby is up to speed.
Encourage them to treat their infant like any other baby... have portraits taken, send out birth announcements, anything that any other parents would do to celebrate their miracle baby. They have finally been blessed with their baby. They want their son to know they welcomed his arrival, and weren't uncomfortable with him when he arrived.
They could check around to see if their are any programs within their school district that would help support a family of an infant with special needs. I'm not implying that the baby will be intellectually involved. I am saying that if the parents can find a network of other parents who are going through something similar, they might find an additional level of support.
You might see if you can locate an instructor for "Baby Sign." I taught my husband and my infant son sign language. A baby's intellectual abilities can handle communication. The muscles of speech just aren't able to until they are older. The hands of a baby; however, CAN handle simple signs! It helped immensely with lessening my son's frustrations. We taught him eat, drink, milk, please, thank you, more, play, sleep and others (his colors as he got older),etc. If both parents know it, and they use the signs whenever they verbalize it, and while going through the activity (sign milk when giving the baby their bottle), the baby will pick it up, and usually fairly quickly. This might be very helpful for them and will certainly help their baby lessen his frustration when he's hungry, tired or thirsty. My son started responding and initiating signs when he was less than six months old.
Someone suggested gathering things a baby with a cleft lip and palate would need that might be different from what other babies need, and I think that is brilliant!
You are a good friend. Continue to be there for them.
It took 14 years for us to get pregnant with our son. I know how eagerly they have been waiting his arrival. I don't know what they are going through, but I do know they are lucky to have you!