"Mostly", but I would also be totally fine with "all the way" as well.
Mostly I just want to be able to get more interesting screenshots with my babies than someone bending over the bassinet. I'd like sims to at least be able to carry them around and sit down holding them in their laps. I mean, we're getting a rocking chair with the knitting pack. I want sims to be able to rock in it with their babies. I would also like babies to be real sims with a rig that I can make custom poses for.
Being able to edit them in CAS would also be awesome. More clothing options. Customizable appearance options. "Got a green alien baby, but I wanted purple!" That sort of thing.
But more game play with them would be cool and I would be excited for anything added. Babies in real life are learning so much in that first year of life. They could have motor, interpersonal interaction, and sound making skills (with appropriate animations) the very least.