I did not hate it, as many people seemed to. Did I think it was the best episode ever, no, but they have definitely done worse. I did think that the emotion still did come through and Sara R. got a chance to show off her amazing pipes. I also didn't know that Bailey was a singer, so I learned something new. But some of the songs didn't really make sense if they were supposed to be happening in Callie's mind.
As for the storyline, that 1 lb 1 oz baby is not meant to live -- that is just way to scary. And of course, now that Mark and Jessica Capshaw have worked things out, the baby basically has to die. I hadn't heard that Addison was going to do a fly-by, so that was kind of a nice surprise, except for the fact that they gave her almost no interactions with people. Christina's future seems to be uncertain in a few ways now, and Alex has another girlfriend who will leave to go be a Charlie's Angel, so he's right about Seattle Grace Mercy Death (hah!) and girlfriends for him. I thought that Derek and Meredith in the elevator was sort of touching, and I liked that they showed how other people being pregnant affects the ones who are struggling to be pregnant.
I still think this season is better than last year and so while this episode was a little off, it didn't kill the momentum for me.