Morgan. Loves. Babies.
He's always been good with my son (now three years old), and is very tolerant of all the three-year old things that he's subjected to. They play together, wrestling and racing, he lets the boy hang on him, etc. If we are out in the front yard (unfenced), Morgan will bark if my son goes out of sight. He's just a good big brother-dog. I do have to keep an eye on them together, though, because my son can get too rough, and Morgan is so patient that he won't do anything to defend himself.
But I had forgotten how much Morgan loves babies until my daughter was born this spring. Morgan just wants to touch her. He will give delicate little kisses on her bald head if he thinks nobody is looking. He worries if she cries. When she's on the floor, he will scoot, scoot, scoot closer and sigh happily when she grabs handfuls of his fur. He will sit and listen very politely while she "talks" to him. If I'd let him, I know he would try to sleep in the nursery.
ETA: Regarding children that aren't "his", Morgan is still a huge fan of babies in general. Wants to see them, sniff them, nuzzle them, kiss them if he can. Older kids, he can be kinda indifferent/ADD about. He doesn't mind kids coming up asking to pet him, but a lot of times his reaction is along the lines of, "You are going to pet me? Yes, I would like tha-there's a squirrel over there."