Dialogue is as follows:

Keeper Remulos (upon beginning the quest): Come <player>, the lake is right around the bend.
Keeper Remulos (upon arriving at the lake): Stand near me, <player>, in case anything should go wrong.
Malfurion Stormrage: Remulos, old friend. It is good to see you once more. I knew this message would find its way to you - one way or another.
Keeper Remulos: It was shrouded in nightmares, Malfurion. What is happening in the Dream? What could cause such atrocities?
Malfurion Stormrage: I fear for the worst, old friend. Within the Dream we fight a new foe, born of an ancient evil. Ysera's ancient brood has fallen victim to the old whisperings. It seems as though the Nightmare has broken through the realm and seeks a new host on Azeroth.
Keeper Remulos: I sensed as much, Malfurion. Dark days loom ahead.
Malfurion Stormrage: Aye, Remulos. Prepare the mortal races.
Keeper Remulos: You have been gone too long, Malfurion. Peace between the children of Azeroth is tenuous at best. What of my father? Of your brother? Have you any news?
Malfurion Stormrage: Cenarius fights at my side. Illidan sits upon his throne in the Outland - brooding. I am afraid his loss to Arthas proved to be his breaking point. Madness has embraced him, Remulos. He replays the events in his head a thousand times per day, but in his mind, he is the victor and Arthas is utterly defeated. He is too far gone, old friend. I fear the time may soon come that our bond is tested and it will not be as it was at the Well in Zin-Azshari.
Malfurion Stormrage: Remulos, I am being drawn back... Tyrande... send her my love... Tell her I am safe. Tell her... Tell her I will return... Farewell...
Keeper Remulos: Farewell, old friend... Farewell...
Keeper Remulos: Let us return to the grove, mortal.

You get to see Malfurion Stormrage on this quest. Pretty neat.

1000 Rep for this part of the quest with CC.