My biggest issue with rage is that it is generally impossible to even use most of your global cooldowns without a big angry boss smacking you in the face. This makes soloing (and offtanking) painful to a degree that nobody else in this game has to deal with. Bonus rage from white swings while wearing a shield could work, either as a multiplier or a flat bonus.
I remember back in early beta, Ghostcrawler said something to the effect that we should be getting more rage simply from doing more DPS. Unfortunately, while this might be true for Feral Druids who gain rage any crit (and also have a significant amount of crit on their gear) this is simply not true for a protection warrior. I'm sure the rage normalization mechanics don't help the matter any.
In any case, recently Ghostcrawler stated that it is Blizzard's intention to see equal representation in arenas for all specs. In order for this to ring true, something is going to have to be done about a Protection Warrior's rage generation, and simply generating rage from avoiding attacks isn't going to cut it for obvious reasons. With this in mind, I am going to remain hopeful, though I am not by any means going to hold my breath.
[18:19:08] [R] [80:Neuter:1]: if bush can dodge a shoe, you can dodge the wall