Since they have announced the Demon Hunter Hate/Discipline is being changed, it sounds like they are making Hate like Spirit and Discipline like mana. That might be cool, we'll see.
In my opinion, it would be really cool and unique if the DH didn't USE UP resources to perform spells, but instead HATE/DISCIPLINE were a scale. When using abilities it pushed the scale towards either Hate or Discipline, and you needed to keep a balance between the two. Attack spells would push your balance toward Hatred, and utility/defense/cc spells would push you towards Discipline.
Sometimes, you would want to go far into one or the other, but most of the time you would want a good balance. For example, if your meter gets higher into hatred, you do a bit more damage (20% max), but because you lack discipline you take a LOT more damage (200%). If it gets to disciplined, your attack speed drops signifigantly (50%), but you gain more defense (~20% less damage taken).
What do you think, or post your ideas. (Posted this yesterday in general but if fell off in 10 seconds).
The Hate/Discipline scale doesn't really make sense to me in the context of how they want Hatred and Discipline to work right now. Hatred is meant to be a rapidly regenerating resource spent on most of your aggressive abilities and Discipline is meant to be a very, very limited defensive resource or a resource you use in preparation for a fight (Sentry, companion, caltrops). The idea of a scale immediately kind of kills off the rapidly regenerating part of Hatred (You naturally are at a state of 0 discipline/full hatred? That would defeat the preparatory nature of how several Discipline abilities work right now), and implies that during a fight you will absolutely have to use Discipline abilities to continue fighting even if you don't necessarily need to use a defensive maneuver right there and then.
There are probably going to be fights in multiplayer games where you won't necessarily become the target of what you're fighting, so you'd have situations where you'd have to arbitrarily tumble/smoke screen/lay a Caltrops under you (Can caltrops be tossed? Last I heard it is just applied where you're standing) when it was completely unnecessary as a defensive ability, and that may leave you running low on Discipline in the future when you may actually need it.
So to make a Hatred/Disc scale work, they'd probably have to significantly change the Discipline abilities and add some new ones. With how the skills work now, though, I think the 2 separate pools that start at full and regenerate at different rates makes more sense.
Also, I could swear I've seen Blizzard comment on this idea and say it's not what they wanted to do, but I can't find that anywhere.