Totally worth the wait! Enjoyed absolutely everything of the episode. All storylines went to rare, original and interesting ways. It gives a lot of thread to cut for the rest of the season (save the awful 8x24 "flight", which almost ruined it all)
A) Music. Totally nailed it with the musical choice. I highly recomend anyone to hear "the same", "skin", and "New York", three incredible emotional songs.
B) Plot coherence regarding "sudden events". Absolute everything was unexpected, from those funny moments (Cristina imitating April), the adoption twist, the alergic reaction, to the news that it was Lily's birthday. Everything, out of the blue. And the narration was up to the plot (finally!).
C) Crash. The most dramatic case I've seen in a while. Loved how Lily was played, and how she managed all the pressure and how she took those unthinkable decisions. While she was not having it at all, she pulled strenght out of nowhere! And this show rarely shows us the worst case scenario or everything going wrong (like in 5x22 bus crash). And I have to say that this was one of Ellen Pompeo's strongest performances in a while. Also Alex was well played. Also, the glass-in-the-eye thing (although gross for some) was a good way to show that Julia is a serious girl for Mark, and that Lexie has a lot to consider if she wants Mark to come back at some point.
D) Teddy drama. Also one of her best performances, laughing and crying in the same episode. Excellently was how the story was being written, and how Cristina handled the situation. What a twist was to hear that Teddy needed her and they had to lie to her in order to go on in the heart surgery! And an interesting plot for Teddy.
E) Again, even if the plot was terrific, they're treating Avery like an idiot and an inexperienced person, which was the only flaw of the episode (esp. 8x09). But Callie reacted well to this, and took all the responsability.
F) Even if the very ending was unreal for some, Grey's Anatomy plays has played with this posibilites (7x20, 5x22). Yes, adoption agents do not tend to bring requested babies home like pizza, but actually in this case, it made it totally unexpected (again, the "suddenly" plot) and it was incredibly touching.
Excellent episode, an awesome way of continuing lots of ongoing storylines. One of my favourite episodes, and clearly the best of the season -enjoyed it more than 8x09)