In this video, he talks about what he confirms are changes. The assault phase was the one I thought was one of the coolest ideas for starters.
The gist of it if you don't want to look at the video is that if you declare the assault, you go first. So as an example, Orks would attack Space Marines first on the first turn of the assault. This includes your Nob with the power klaw.
I'm curious to hear thoughts about this. My thinking is it's a significant change that doesn't break the game. In 6th, the assault was nerfed so you couldn't charge out of reserves, hitting Space Wolves and drop pod armies pretty hard. The entire game shifted at that point to a shooting game and has been there ever since. As far as this change and not breaking the game, it's enough of a change to give assault armies an advantage in the phase they need it and not make shooting armies useless. Everyone still gets their overwatch, you still have to have enough bodies to survive to get into assault and you have to assault with enough to clear a large portion of your opponents guys before they hit you back.
I personally like the idea. I think it will balance the global meta a bit where either players are having to consider assault defense a little more or dust off their old Blood Angels/Orks models and try to dominate in close range combat.
Of course, this is purely speculation but I'm curious to hear other thoughts.
Lastly, as a disclaimer, I just recently popped open (finally!) my Ork Battle Force box that I purchased back in '14. I'm seriously looking forward to playing Orks if this change comes through!