universal mechanic for weapon-using classes, like psionic classes and power points, except that not every class is necessarily going to get maneuvers as part of the deal.
I agree with having damage scale as opposed to attack bonuses. 3rd Edition's three separate base attack bonus rates made it a nightmare to balance monsters, especially with melee-oriented characters that dared to multiclass. At least this way more characters will be able to land a hit, though depending on how things scale it might not be a good hit.
On a similar note this allows low-level monsters to remain viable threats, even if it means having to gang up in order to inflict a meaningful amount of damage. Hopefully this means we can avoid having to scale up their level as we did in 4th Edition (resulting in some strange things like level 10 goblins), or spend hours piling on class levels and re-calculating attack bonus, saving throws, skills, feats, and more as with 3rd Edition.
I know that expertise dice started out as the fighter's shtick, but to me it really made a lot of sense to give the rogue (and the monk, and probably some iteration of the ranger, paladin, barbarian, etc) maneuvers; they are simple, dynamic, and for those that took issue with 4th Edition not limited by the encounter or day (though Mearls makes mention of that being a possible optional module near the end...dun dun duuun).
Even so some people are upset that the fighter has to share its nice things, but I do not see an issue with it because maneuvers are not universally available; a rogue cannot take Deadly Strike (so the fighter gets to regularly burn dice to dish out bonus damage), fighters cannot take Skill Mastery, and only monks can run on water thanks to Step of the Wind. So even ignoring class features, to a point there is some form of niche protection, though I wonder how well things will be preserved with multiclassing.
While I am all for giving the fighter some more iconic features, I think Parry is a pretty boring way to go about it. What about swashbuckling rogues? What about monks slapping aside swords with their bare hands? What about armor? I hear a lot of complaints about how a good Dex and light armor is better than going the heavy route, so why not give them options that make them even better in heavy armor, such as damage resistance or even just a plain ol' AC boost?
I am baffled that some might think that expertise dice are too complicated. Are players really forgetting if they used one or two dice less than a minute ago? Do not get me wrong, I am all for giving the fighter full access to dice for actions and reactions (some would argue that it is better to just use them for bonus damage instead of anything else, so this would encourage people to use things like Parry and Protect), I just cannot believe that it is because it is too difficult to keep track of.
Feats giving out extra maneuvers sounds interesting, but if they are all fueled by expertise dice then it still restricts it to certain classes. Granted if more classes have access to expertise dice it will at least end up being a lot more flexible than in past editions (even 4th Edition, which made it very easy to make functional duel-wielding fighters, rangers, barbarians, and maybe something else I am forgetting about).
Maybe if said feats granted bonus expertise dice? Actually, I wonder how expertise dice will scale through multiclassing; it would suck to take a second attack that does all of 1d4 damage at 5th-level.
Speaking of scaling, another issue is how magic works in the bigger picture given that most spells do not scale. They do one thing, no matter what level you are. In past editions many spells automatically scaled, often with a damage cap. An iconic example is fireball, which dealt 1d6 damage per level, up to 10d6. In 4th Edition this was also handled via power swapping: eventually you got to a point where you could exchange one power for another (though a few powers scaled up automatically).
Not so in In 5th Edition where there are only like, two spells that I can think of that scale--magic missile and thunderwave--and that is only if you memorize them using higher-level spell slots. There are still a couple potent save-or-screws, such as hold person and polymorph but, eh...if you follow this blog at all then you know that for me the traditional D&D magic system is another can of worms entirely.
In short I am behind the idea of scaling damage instead of attack bonuses and dice-fueled maneuvers, so long as they are thematically tied to class. I can also get behind feat-granted maneuvers, though it depends on how it gets executed. Same goes for the optional encounter/daily stuff. As always, magic needs a major overhaul.