Congratulations!!! I just went through the same thing.
I started out by talking about the baby with my grey. I also talked about all the names I was thinking about for the baby. After the baby's room was set up I took Taco into the room and let him perch on the crib, check out the toys and I sang the songs that I now sing to the baby.
Taco has taken everything in stride. I just have to remember that I can't hold Taco and the baby at the same time. Taco will bite me if I am on the phone or holding the baby.
If you think you can handle the extra cleaning and care of another bird I think it would be a good idea. Please keep in mind that no matter how much energy you may think you'll have after the birth, you wont:P
Good luck, everything will be fine in the long run.