I'm playing resto druid right now and I partly agree with what you say about not being very compelling to play those classes, right now I sill play resto because of my gear and I like to beat other healers with the less powerful class, reason I won't play holy paladin in a raid environment, HOWEVER rewarding challenge and fun? Challenge modes, you can do them with any healer and is a different puzzle, I know people don't like them because of the timer or the lack of gear, but the feeling that I'm getting better by trying this and that my healing is making the difference, challenge modes beats raiding at this moment, if you want a reason to continue enjoying the healing role, CM are the way to ge (hard to get a group of dps and tanks tho).
I think that the core of the wotlk is the best thing for healing, not because it is the max in skill or something, but is the more engaging, is what more people want to play, like the comment I quote below.
Yes, I think that we need something closer to WotLK to engage more players, however something else like triage at the same time (working this idea for 2 months, haven't finished yet) to engage the skilled players too. Idle time, because I need to wait for my better spell to come out of CD, or I can't cast my filler because my total mana is fixed and I have to cast a "better" spell worth of my mana isn't engaging, when pushing spells all the time is a bad thing we have a problem with the healing model (hint if you are casting Nourish you are doing it wrong). That said, I think most of the classes will spam whatever the next tier, I'm not there yet but there are reports in EJ that resto druids can spam rejuv all the fight with 17k spirit and the LMG (hint 2: until you can't reach and confirm this, reforging out spirit is the way to go, maybe even instead of full rejuv spam more throughput is the way to go).