First off, the change to Heroic Strike is huge. At present, HS is an on-next-melee ability (that is, when you depress the HS button, your next white attack is instead replaced by HS) that does extra damage, costs rage and has a high threat component. This means that as rage approaches infinite for a tank or DPS warrior, the reason to not convert your next attack (which would normally generate rage) to a Heroic Strike (which will instead bleed rage off but give you more damage and/or threat) becomes nonexistent. By making Heroic Strike into an instant attack with a variable rage cost, you've made HS much more situational, instead of its current role as the "If I have at least X rage there is no reason not to HS" attack. The model example for HS given makes it much like Execute, so we'll see if that's how it actually shakes out. There doesn't seem as if there would be much need for both abilities.
Second, making attacks provide a fixed amount of rage rather than a scaling amount removes some of the inflationary aspect of warrior gearing. Hitting harder won't automatically mean more rage to use specials with. A warrior with 4,000 AP will get as much rage per hit as one with 6,000 AP. However, gear will still have some influence over how much rage you generate because of stats like critical hit and haste, which each will have a mechanism for increased rage generation. Haste will increase the speed of your swings, giving you more attacks and thus more rage, while a critical hit will multiply the rage of a hit by 200%, meaning that more swings and more crits will still provide more rage. In theory, this will mean that both tanks and DPS warriors will find haste and crit more attractive for ensuring smoother rage generation, although we'll see how this plays out. Similarly, by basing rage from damage taken on the warrior's health you can have damage increase without having it automatically supercharge the tanking warrior's rage pool. Clearly this is aimed at making warrior tanks have to conserve rage when tanking. Expect negative effects on warrior tank threat, unless baseline warrior tanking damage is vastly improved.
Furthermore, by making various warrior shouts (Battle and Commanding, at least) provide rage instead of costing rage (à la death knight ability Horn of Winter), warriors will effectively have more ways to increase rage when it becomes necessary to do so, since this model of rage generation is more vulnerable to bogging down in rage starvation.
The concept of normalized Rage may leave a negative impression on some veteran players, as we tried it once before in The Burning Crusade and it wasn't successful, resulting in them feeling weakened. However, we think that the concept is still sound -- it was just that the previous implementation didn't balance the values correctly, leading to players being Rage-starved. That is not the goal. As part of the change, we want to give warriors and druids a lot of ways to control their rage, so even in the worst-case scenarios they won't feel like they lack the resource to do their job.
I was one of those players, and it wasn't a feeling. We were very much weakened. Dismissing it as a "feeling" is troubling, as are reassurances that if they balance too low, they can adjust upwards. It took nearly six months for an upward adjustment to happen in Burning Crusade
. That being said, I am cautiously optimistic here. If the problems inherent in rage normalization are addressed and warriors are given the means to control rage more than present (Bloodrage is currently the only means to produce rage when it is needed, but simply tacking rage gen onto Battle Shout is not enough, in my opinion), then this model has the potential to allow for a more balanced experience for warriors unfortunate enough to not be in the absolutely best gear available. It will cause warriors to lose forever their exponential power increases at highest levels of gear, but since the majority of warriors never see those levels, it should benefit the majority of the class.
It will also allow for tanks to gear up without feeling penalized for doing so by losing the majority of their rage, again, if handled correctly. Rage will be much more variable for tanks
and will be gained for doing what tanks do -- avoid or mitigate as much damage as possible. While you'll gain less rage per damage you take as you gear up, hopefully rage gained from other sources will help avoid starvation.