Like many other people, I read with interest the rumours concerning the next edition of the Warhammer 40,000 core rule book. Being a bit of an old timer (meaning I've been playing since Rogue Trader days), I thought that I would offer up some views on the rumours and what my take on them is.
(1) Armour save modifiers. In the current rule book, every miniature gets a fixed saving throw to represent how good their armour is. Some weapons are designed to bypass almost any armour at close enough range (plasma and melta all have a low AP for instance). This works well, as armour should stop some shot types but not others and the system is relatively simple. On the other hand, the proposal to modify saving throws based on the weapon used is an old idea that's been done before. Sure, it works nicely. Until a new release comes along that says you can never alter my saving throw. And then power creep might well happen. Furthermore, this rules change favours cheap horse style armies. Why take space marines any more if they only get a 5+ save from bolt gun rounds when you could just have more wounds by taking more irks or tyranids? In short: I don't like this change even if it might make some narrative sense to some people.
Also "This topic comes up almost as often as Sisters of Battle… so we're going to bring them back" -- did you interpret that to mean sisters of battle are being brought back as well?!
(2) Variable movement rates. This is bad. It makes the current system more complicated than it needs to be. Currently it is 6 inch or 12 inch moves for almost everything-- nice and simple. I really don't want to have to remember five or eight or twelve different movement rates and try to think about how fast my opponent will be moving in their next turn. Getting rid of movement characteristics was a good thing to my mind. This complexifies things and risks making the game slower -- at least at first. In short: I don't like this either.
(3) Striking first if you charge in to combat. Charging is already rewarded through bonus attacks. That said, being able to strike first due to charging is a very nice idea and one that I do not think will slow the game down. I am all for this one as it'll bring about new tactics that I think makes more sense. The worry for me here is what it'll do to 30k.
(4) Different ways to play. Looks like an Age of Sigmar import. This is actually all good in my opinion though. I would encourage folks to look up the Age of Sigmar system for the ways that can be played. I actually like it.
(5) Morale. The proposal of moving to a "kill more squad members if you lose" is okay and feels like what happens to fearless or daemon units. I can't quit tell if units are still going to be fleeing or not though. I hope fleeing still happens as it's fluffy!
(6) Command points. Urgh. A messy way to solve the mess of formations being introduced outside of Apocalypse about a decade ago. It will work in the short term and until codex creep happens. Or until a big bonus of rerolling everything happens. It has the potential to be game breaking if done badly with the bonuses getting out of hand. I'll take a wait and see approach for this one overall.