Obviously we already know most(all I think) of the named npc in Theramore died but there were quite a few..unexpected people who died in the book as well.
Rhonin readhair(I'm sure people have seen the spoilers)
Kinddy Sparkshine(a gnome made specifically for the book but I think was pretty important to the what happens to Jaina)
Thaddus Stoutblow (Wildhammer)
Horran Redmane (7th Legion)
Tolliver Houndstooth (http://www.wowpedia.org/Tolliver_Houndstooth)
And a special farewell...Marcus Johnathan. You were always one of the first to great any Alliance player to Stormwind /cry