Here is a list of characters from the book, whenever someone gets confirmed for a role, just copy paste the list and add the actor

Bilbo Bagins
Gandalf - Ian McKellen
Thorin Oakenshield
Balin
Kili
Fili
Gloin
Bombur
Oin
Dwalin
Bifur
Bofur
Ori
Nori
Dori
Elrond - Hugo Weaving
the Great Goblin
Gollum - Andy Serkis
Beorn
Thranduil
Bard
Master of Lake Town
Smaug (voice)
Bolg

I'll lock this for now so we don't get any spam. But good idea, rodu. It's always good to have a running list of characters when they get matched up with actors. When we get some announcements, I'll unlock this and edit the list.