I agree, just get in straight away and say something like "omg - what great taste, thats what we are naming this little one if he is a boy too!"

I had a friend who tried to change the name slightly of their newborn to my ds who was 3 mths older. I think she was a bit embarrassed but I didnt care about it, after all its not like I am the only person in the history of the world to call my child that, even though its not a common name.
They were welcome to use it and I wish they hadnt tried to pretend that they werent using the same name. Better to be upfront I think.