First, Do Some Harm

Gone are the days of the pacifist healer sitting in the back row patching up the dpsers doing the dirty work. Come Cataclysm, with the new mechanics, abilities, and talents showing up in beta, it's prety clear that Blizzard wants us healers to get down off our high horses and get our hands a little bloody. So healers? Let's get ready to rumble.

Pre-Cata

Prior to cataclysm, most healers really only did damage when they were super bored. A healer spending mana on a dps ability would be pretty much unthinkable on a progression encounter, much less talent points, with only a few exceptions.

• Holy Paladins in Wrath got Judgements of the Pure, which, combined with Enlightened Judgements, allowed holydins to judge from a distance, and in fact, were encouraged to do so at least once every minute to optimize their healing.
• Holy Priests have frequently found themselves using their Shadow Word: Death backlash to force a stuck Prayer of Mending to bounce to another raid member.
• Holy Priests have Surge of Light, which prior to WOTLK could only proc a free smite, instead of a Flash Heal like it does today. This was generally regarded as a poor talent prior to being changed.

Other than those, most healers had no real incentive or reason to dps while filling a healing role. Even dead time was better spent regenning mana out of combat.

New Talents/Skills for Healing Classes in Cataclysm

In cataclysm, across the board, we're seeing dps talents showing up in previously healing exclusive trees.

• Shaman
  Resto shaman playing with a cataclysm talent calculator will find that it's nearly impossible to build a pve restoration build without being forced to take one of the new "hybrid" talents that encourage resto shaman to dps during periods of light healing.
  • Focused Insight allows you to get a cheaper and more effective heal after any shock spell (this does not include Wind Shear).
  • Telluric Currents gives you a portion of your mana back from casting Lightning Bolt relative to the amount of damage done. Interestingly enough, on beta, many shaman were able to get to spellpower levels that would actually cause lightning bolt to be a net gain in mana, although Blizz has since clarified that this is not the intended purpose and presumably the talent will be rebalanced as needed.
  I'm not crazy about either of these mechanics. For Focused Insight, I feel that Shaman have many other ways to "charge up" their next heal, including Tidal Waves and the new Unleash Life ability. Telluric Currents confuses me, because we're constantly being told by Blizzard developers that we've had it too easy in the past and they want mana conservation to be an issue going forward. Even if they're cheap, I can't see how encouraging Resto Shaman to waste mana on lightning bolts is part of this overall strategy.
• Priest
  Disc priests have always had the schizophrenic Penance which contextually heals or damages based on who the spell's target is. Now Holy is getting a somewhat similar spell called Holy Word: Chastise that is an instant damage ability by default, but can convert into either Aspire, Serenity, or Sanctuary, based on the Chakra state that you are in. The mechanic sounds confusing, and potentially a nightmare for keybindings/macros, but the abilities themselves look really cool, so it's definitely something I'm looking forward to playing with. Beyond that, priests of both healing trees are getting a lot of talents that encourage smiting.
  • In the second tier of the Disc tree, priests get a talent Evangelism which looks like a pure dps talent until you see it's dependent Archangel which restores mana and gives you a short healing boost. This definitely fits in with the "dps during dead time" model nicely, and gives you another nice mana regen and healing boost cooldown.
  • The disc-only talent Atonement is probably one of my favorites of the new hybrid talents; you heal low health allies near you when you smite. Simple and kind of fun. Dovetails nicely with Evangelism.
  • I'm not as excited about the Holy tree's Trinity because it is useless unless you have enough downtime to smite three times in a row, and your haste boost is only good for the next 12 seconds. You really need to time this effect right to make it useful, whereas Archangel is much more adaptive. Still, this talent is a prereq for the new Surge of Light, which most people will probably want.
• Paladin
  The aforementioned long range of Enlightened Judgements is now actually becoming baseline for all Paladins, which is kind of a nice treat. In addition, they get some new and somewhat confusing new dps/healing hybrid talents.
  • Denounce looks basically like the old pre-wotlk Surge of Light. At 2 points it reduces the cost of exorcism by 75% at its base, and gives your holy shock the ability to proc fee exorcisms. Additionally, the free Exorcisms can crit, allowing you to proc other talents like Conviction for free.
  • As I said before, the old Enlightened Judgements range became baseline, and the new one causes your judgements to heal yourself. Healing yourself is pretty boring, but it's not a bad filler talent, given that you have to judge at least once a minute.
  I gotta be honest, a lot of these changes confuse me, because I've never really raid healed on my holy paladin. I'm just gonna keep my mouth shut.
• Druid
  Druids, most dramatically, actually could only cast restoration spells in tree form in the past. Now not only can they cast all their Balance spells in tree form, but they even get a bonus to Wrath while in Tree form. Additionally, there is a new talent that encourages dps.
  • Fury of Stormrage makes Wrath FREE and allows Wrath to proc instant Starfires. While this seems like a strange mechanic for healing, any free spells are awesome. Not only does your mana regen continue as in out of combat, but I would assume that these free spells can still proc talents and abilities like Omen of Clarity. Anyway, this talent is a prereq for Malfurion's Gift, so I think all Resto druids will be picking this up anyways. Enjoy it you guys.

So as a whole, I'm intrigued by the hybrid aspect of these talents, and there are some of them that I think work really well without interfering in the primary role that healers signed up for. Obviously these will all be tweaked and edited and modified before cata goes live, but it's definitely something I'm keeping an eye on.