I played my first game of 8th tonight and already found something that seems so powerful as to be broken, except it can't be broken because it was built into the core of the game as an obvious feature.
A Weirdboy costs 62pts. One power that they can automatically know is Da Jump. Da Jump allows you to select a nearby unit of Orks, teleport it anywhere on the board that is at least 9" from an enemy unit, and set them down.
That unit can charge. You only need to end up within 1" of an enemy unit for the charge to be succesful. Orks can re-roll charges. You need to get an 8, with a re-roll.
Da Jump requires a 7+ on 2d6 to be succesful. HOWEVER. For every 10 Orks within 10" of the Weirdboy, you get a +1 on that roll. With a single horde of Ork Boyz (Which will be nearby anyways, since you're teleporting them,) you need a 4+ to manifest successfully. With two nearby hordes, you need a 1+.
This combo costs 242 points. For that, you can reliably assault with 30 Ork Boyz against any enemy at any spot on the board. This can be done with as many units as you want, points allowing.
Cheese is dead. Long live the cheese.