White Walkers, wights, and the blue-eyed beasts who ... This is going to come in handy -- it is known. The summoned army of wights and Walkers announces its arrival with a booming winter stormcloud.

While we know Sam killed his own White Walker with an obsidian blade ... does seem to be setting up the possibility of a Westerosi army equipped with all manner of badass Valyrian weapons.