The final film is the Hobbit trilogy (still scratching our heads how that happened) is coming - and since it's called "The Battle of Five Armies," there'd better be one pretty great battle in it (involving five armies, we presume). From the looks of the concept art, it will be worth having to stretch the story of The Hobbit out into 3 (THREE!) films.
Gonna be honest - kinda feels like WETA dropped the ball with that last sequence. Expected a little more detail and 'epic scope' with the designs, but maybe they just ran out of time? Regardless, it's gonna be pretty jarring for all the armies to suddenly turn into multi-colored arrows and circles at the last second, but I guess we just have to trust the genius that is Peter Jackson!