The Price of Peace

Just completed this quest today. I might be wrong, but I believe this becomes available once you've defeated N'Zoth the Corruptor.

After talking to Shaw and Valeera, you can go over to the area with the bonfire and the trainers to catch a conversation between Shandris and Tyrande as well.

Spoiler

Shandris Feathermoon says: You spoke harshly to King Anduin, Tyrande. The kaldorei can ill afford to shun the Alliance. They have provided aid and comfort to us in these dark times.
Tyrande Whisperwind says: The young king is foolish to trust our enemies. Harsh words should be the least of his fears.
Shandris Feathermoon says: The Banshee Queen no longer leads the Horde. Those who do seem more inclined toward peace than war.
Tyrande Whisperwind says: If the wolf is rabid, it matters not who rides it. Sooner or later, the beast will bare its fangs.
Shandris Feathermoon says: You are dearest to my heart, Tyrande. I beg you, let go of the Black Moon's rage and embrace the mother's light once again. I could not bear to lose you to darkness.
Tyrande Whisperwind says: Know this. My hunger for vengeance will not be sated so long as Sylvanas Windrunner remains free--and until I know why Elune abandoned her children.
Shandris Feathermoon says: Tyrande! Do not say such--
Tyrande Whisperwind says: I will tarry no longer in this city of men. Let us leave for the boughs of Nordrassil.
Tyrande Whisperwind says: From there we will dispatch the Sentinels to every corner of Azeroth. Let no one rest until the Banshee is found!

Quite a lot of lore going on after the cutscene, perhaps more relevant than said cutscene.

See Peitho's post for the Turalyon and Alleria cutscene which I've missed.

Valeera and Shaw speak right outside the Embassy and are hard to miss, as they'll start talking if you do basically anything.

Valeera & Shaw

Spoiler

V: The bitter war is over, yet it seems few among us are in the mood for celebration. Our young king least of all.
S: A great weight rests upon King Anduin's shoulders. I fear his burden won't get lighter anytime soon.
V: And what of you, Shaw? What is there for Stormwind's spymaster to do in a time of peace?
S: You know as well as I that a true spy never rests. There is always a new conspiracy to uncover. That said, I may find a bit of time for myself.
V: Just yourself?
S: There is someone I would like to... get to know better. But such things are best taken slowly. Carefully.
V: Spoken like a true spy. Just remember, happiness is a fleeting thing. Find it while you can, Shaw.
S: Perhaps I will, Valeera. Perhaps I will.

---

Shandris and Tyrande are standing slightly to the back (near Genn), whom are definitely not on the same line as to Tyrande's rant during the meeting proper.

Shandris & Tyrande

Spoiler

S: You spoke harshly to King Anduin, Tyrande. The kaldorei can ill afford to shun the Alliance. They have provided aid and comfort to us in these dark times.
T: The young king is foolish to trust our enemies. Harsh words should be the least of his fears.
S: The Banshee Queen no longer leads the Horde. Those who do seem more inclined toward peace than war.
T: If the wolf is rabid, it matters not who rides it. Sooner or later, the beast will bare its fangs.
S: You are dearest to my heart, Tyrande. I beg you, let go of the Black Moon's rage and embrace the mother's light once again. I could not bear to lose you to darkness.
T: Know this. My hunger for vengeance will not be sated so long as Sylvanas Windrunner remains free--and until I know why Elune abandoned her children.
S: Tyrande! Do not say such--
T: I will tarry no longer in this city of men. Let us leave for the boughs of Nordrassil.
T: From there we will dispatch the Sentinels to every corner of Azeroth. Let no one rest until the Banshee is found!

---

Seems like there's no mention of the specific Jaina and Anduin conversations yet. They are in a tent to the left of the Embassy. I've been able to trigger two. Wowpedia lists them as one conversation and then one undefined, but I believe it's just these two separate conversations.

Jaina & Anduin 1 (N'Zoth & Sylvanas)

Spoiler

J: The Old God has been vanquished. The Alliance and Horde have ended hostilities.
J: This should be a day of celebration, Anduin. Yet you wear your troubles like a crown.
A: I'm so glad that after all you endured, you have found peace within your heart, Jaina. I can't say the same about myself, though. Not yet.
A: Sylvanas is out there somewhere. Until she's brought to justice, I don't think Tyrande or Genn will truly consider the war to be over.
J: The Kul Tiran fleet is scouring the seas, and Shaw has spies searching every dark corner of Azeroth. She can't hide for long.
A: I don't believe she will. Which is exactly what concerns me.

Jaina & Anduin 2 (Fordragons)

Spoiler

A: I saw you speaking with a messenger from Kul Tiras, Jaina. Is everything alright?
J: Nothing to worry about. It was a letter from a certain eager cadet asking to see Stormwind... and to learn more about her father.
A: Taelia. Please tell her that this isn't a good time for visitors.
J: She deserves to hear the truth, Anduin. From you.
A: Tirion Fordring himself made us swear that we would keep the secret of Bolvar's fate. You made that vow just as I did.
J: I remember your father once telling me that the hardest thing about a promise isn't keeping it, but knowing when it's right to break it.
A: Bolvar was a noble man. To know that he sits frozen upon that accursed throne, devoting his very life to keeping the monsters at bay...
A: It breaks my heart. I can't bear to see it break Taelia's, too.
J: The decision is yours, Anduin. But if she learns that the truth was kept from her, it will hurt her all the more.

---

Tl;dr. Shaw's lonely, Valeera's bored, Shandris' concerned, Tyrande's pissed, Jaina's relieved and Anduin's manduin. Pretty much.