I would just note that 4e has been pretty darn good about not letting one role bleed into another. There aren't powers that let non-leaders heal (paladins are really just about the only minor exception and it is hardly accidental).
Sorry, but are you kidding? Almost every non-leader class has at least one:
Assassin: Claim the Dead
Avenger: Renewing Strike
Barbarian: Life Thane Rage
Battlemind: Aspect of Elevated Harmony
Druid: Form of the Primeval Boar (pre-Essentials turning Druids into Leaders)
Fighter: Comeback Strike
Invoker: Death's Denial
Monk: Internal Power
Paladin: Paladins Judgment
Ranger: Wounded Beast
Sorcerer: Moon and the Stars
Swordmage: Rejuvenating Strike
Warden: Bear's Endurance
Warlock: Red Leeches of Nihal (I put this down as an example because it's temporary hit points which amount to the same thing, warlocks actually have several other actual healing powers)
Granted, many such powers are Dailies, but not all of them. And some of these classes have a dozen or more such powers.
Now, if you are talking healing powers that heal others, then yeah, that might be 10% of the 150 to 200 or so non-leader healing powers in the game. But, a lot of them still exist. Remember, a PC only has to have one of them in order to heal.
But compared to previous editions of the game, 4E is probably the most egregious about letting non-healers heal. There is a lot more role bleed over.
And the reason it happens in 4E is because everyone has powers. Everyone is a superhero. In previous editions, not everyone had spells.
There has to come a time when characters are depleted. Previous editions simply depleted the cleric of CLWs and CSWs and whatever. I don't really know what you're after. The characters can survive a certain amount of fighting and then they'll run out of resources and either win, get out of dodge, or die.
I'm after things like Artifacts or (expensive) Rituals that restore Healing Surges and/or possibly Daily powers (possibly with penalties associated with them such as cannot regain healing surges for a week or some such). The game allows someone to be brought back from the dead, but has no mechanisms for getting past 4 encounters per day. Huh?
I'm looking for MMMAAAGGGIIICCC!!!
BOOM, not wimper.
Sure, Gandalf had a restorative, I still want to see even ONE example in literature or any other fiction that wasn't a D&D novel where someone whips out a potion in the middle of a fight, chugs it down, and gets healed. I think fundamentally it is just more satisfying if the hero's own resolve is the source of the power to endure vs having it come in a bottle. Matter of taste I guess.
The Fountain of Youth
In Indiana Jones and the Last Crusade, drinking from the Holy Grail
In "The Lion, The Witch, and The Wardrobe" (1950), Father Christmas gave Lucy a cordial
In "The Slithering Shadow" (Conan, 1933), there was a golden wine that restored vigor and repaired wounds, bringing Conan back from the brink of death to full health.
Granted, they aren't "drinking healing potions in the middle of combat", but then again, that doesn't happen too often in 4E either.
The issue with "the hero's own resolve" is that it's overplayed here. It's allowed to be "every single encounter" or in the case of Warlords (and even Bards), it is every single encounter.
It's the concept that wounds don't exist. We fight and fight, but we don't get wounded. We just get tired and then overcome being tired with personal resolve and cheerleader cheering up. Woo hoo! That concept is really over used in 4E and is not what I consider magical fantasy.
The one thing about 4E that I hope that they restore with 5E is the magic.
In 4E, most every PC has superpowers. Most every PC can heal. Most every PC has supernatural or magical ways to shrug off or avoid damage.
Every PC is a Jedi (i.e. with respect to displaying supernatural abilities).
It's not a matter of balancing the powers. It's a matter of segregating them.
One of the few things I like about Essentials is that some of the PCs now have most abilities that merely increase the umph of a melee basic attack without delving into supernatural effects.
Don't get me wrong. I enjoy playing 4E. I just find the roles and classes to be very overlapping, partially because most powers have supernatural or magical riders or effects. We can't just hit for damage, we have to also move foes or add bonuses and penalties to future rolls or yadda yadda yadda with almost every single power. There is also a ton of bookkeeping associated with all of these effects from most every single power / class feature / item / feat.
Syndrome (to Mr. Incredible): "And when I'm old and I've had my fun, I'll sell my inventions so that everyone can be superheroes. Everyone can be super. And when everyone's super, no one will be."
This is how I view 4E's magic. Everyone has it. Nearly every single monster (except minions for the most part). Every single PC. And they all have it in spades.