Cataclysm Class Rotation Design

MMO-Champion held a contest for writing guides in their forums, and I've been reading through the winning DPS guides since I'm experimenting with so many specs at the moment.  I was struck by a common thread in the advice:
  • "Shadow Priests do not have a DPS "rotation" in a classical sense. Instead, we operate on a priority system, determined by which of our spells should be cast at a given time, given its supposed superior damage benefit over other spells." - Newnoise's Shadow Priest Guide
  • "In contrast to the Fury Warrior who has more of a preset rotation, the Arms Warrior's rotation is a priority based system that constantly fluctuates based upon inconsistant procs and abilities that pop up randomly throughout the rotation..." - Loto Bordeau's Arms Warrior PVE Guide
  • "Alright, the first thing you need to know about frost's rotation is that you're not casting spells in a repetitive cycle. You're conforming to a priority list." - The Ultimate Guide to Frost by Karrok
  • "Cats don't use a set ability rotation; instead we have a priority list of buffs/debuffs/abilities to use." - The Cat Guide, 4.0.3a edition by Mihir
I don't know enough about the endgame to tell whether these guys know their stuff or not, but my personal class impressions back them up; Blizzard seems to have gone out of their way to add some kind of reactive proc mechanic to DPS classes.

This approach makes sense because it provides more room for character performance to scale with player skill.  In a world where bosses like Patchwerk sit still and take whatever players are dishing out, gear and a pre-set rotation can account for the majority of player performance.  Moving to a world where players need to adjust their actions allows more room for superior skill to shine through.  (It also means that a subpar random DPS player in an automatically generated group might be that much further below what the dungeon was balanced for.) 

Then again, I'm also looking at these classes from the bottom up, as I play around with each at level one.  Everyone now has some way to restore HP to either themselves or their pets, generally pretty early on in their character's lives.  The casters all have a spammable nuke and the melee all have an instant attack of some sort.  Everyone can now expect some sort of light-up proc that tells them to drop their bread and butter skills and use some more beneficial situational ability.  Though various classes get various buffs, it seems like these too have been shared around enough to make sure that most raids will have most of what they need without too much suffering. 

It's certainly possible that there are exceptions - the Arms guy says that Fury is EZ-mode, though I'd take that assessment more seriously if it came from an actual Fury player - but the result seems to be that you're getting a very similar play experience as you level.  There are still differences in feel - the hunter's focus mechanic is different, some of the healer DPS specs are locked out of healing by stances, etc - but I wonder whether the similarities are going to start standing out more if and when players spend more attention on rolling up alts.