Congrats to your brother and his wife, I'm guessing their still hurt over their first daughters death but I wish them a bright future for them and baby.
Being an aunt/uncle is pretty exciting the first few times. I have 8 Nephews and 6 Nieces as well as a Great-niece. I come from a pretty large family as you can no doubt tell.
Must of been great to get that news at Christmas time. Would be cool if he/she was born in May, that is Spring time in the USA isn't it? In Australia it's Autumn. Also May babies are the best, in my own humble opinion anyway..