This was a wonderful episode of Yes, Dear and I'll tell you why.
Firstly, it helped us to look into the characters' lives. Sure, we know them. But, this episode created a deeper character by allowing us to have insight into their personae. Sure, they're fictional. But, even fictional characters need to have some depth.
Secondly, despite a different format, it still attained the same level of humor we expect from Yes, Dear. You would expect a "documentary-style" episode rather boring, but the writers managed to add a couple of "laugh out loud" moments for us to enjoy. My personal favorite was the ending when we realized that Kim's father actually manipulated them to name the daughter Emily.
Thirdly, we also got to see the birth of the baby. Time and again, we've seen various television show families welcoming a new addition to their family and it usually they share the same script. Family is prepared, baby is not born. Family is anxious, baby is born unexpectedly, father-figure gets nervous, baby is born amongst the family or family is all in waiting room. Happy ending and there it goes. This was unique in how they presented the birth of the baby.
In conclusion, "We're Having a Baby" wasn't a pivotal episode, nor did it contribute a whole lot to the storyline, but it gave us a change in routine and format, a look into the characters' lives, and the birth of the baby. It was created with much ingenuity. And that's why I gave it a 9.6.