Things that make me nervous:

None of the codexes work now, because all of the rules that get constantly updated.

Why do this when 80% of nearly any given army's detachments are unviable/unplayable now? No fucking way they balance it well.

Can't wait to see how broken this gets.

Neat idea, terrified that they're going to make unclear objective/terrain rules to make it even more wonky.
Things that give me hope:

Supposedly this means anyone in terrain cannot be shot at until it has shot, unless the attacker is within 15". Sounds like a decent way to make melee more viable.

Big change is that you roll your charge, then choose where you go. Also good for melee, makes it not so awkward.

This is nice I am thinking, declutters some rules nonsense.