Ok, so i just heard this and picked something up out of it that seemed rather interesting.
http://www.youtube.com/watch?v=3LoXWPYXkvI
I sure do hear the orc laugh in there, but listen here...
IC_LichKing_SM_12 - 2:11
The voice gets unusually deep, unlike any other clip. He is also speaking about Frostmourne needing more and more souls.
It sounds like a demon voice to me!
Is this the voice of Frostmourne/Shadowmourne (Mainly whatever the ram skull represents)? Will its Burning Legion roots be revealed? What do you think?