My children have my last name and i wouldn't have it any other way. I personally don't agree with the 'it's the done thing' argument. Marriage before having a baby was the done thing once upon a time yet stats came out the other day showing that more and more babies are being born out of wedlock.
Times have changed and women have just as much right as men these days. Anything goes when it comes to naming your child.
I was not willing to compromise on my childrens surname when they were born. I would have fought it all the way to court if i had to. My ex wasn't fazed though. The only argument i got was from his mother and her opinion is incredibly insignificant in the grand scheme of things anyway.