My playstyle is primarily focused on families....but even so I would absolutely NOT want this to be the next pack we get.
Babies are boring, no matter how much you add for them and they also consist of a very, very tiny portion of a Sim's total life. We haven't gotten any substantial new gameplay in nearly a year now ... it would be a real shame if baby's were the focus for the next pack, or even the one after that.
That's not to say I would not like to see this, but after the dry spell we've had, I am hoping for something with a little more 'meat' then that for what is next.