Cool things I saw:
dreadnoughts in ravens took some hits(now take s10 hits if the Storm Raven was Zooming)
you don't get ap2 if you rend vs vehicles, only on infantry
warlord traits are lost if the warlord is killed
blessings can affect units arriving from reserves that same turn
models in a unit with multiple toughness values use their own in challenges
if a model gains Fearless at the start of the movement phase they can ignore Gone to Ground from previous phase
CHAOS MARINE BLASTMASTERS ARE BACK! (they can be taken in 5 man squads!)
That's most of it, there are some interesting things for DE, but Nids and Orks didn't get much love at all. Anything you found that sticks out? Comment below!