in another thread the buff to Holy Shock was brought up. im not so sure the talent is a buff, rather it is modified. with the combining of the +spell dmg and the +healing, it would only make sense to buff the healing spells and require less +healing stat. as it is now +2k healing is pretty easy to acquire yet +2k spell is near impossible. to have dps casters with healing quality stats would be way OP, likewise to have healers with caster stats silly.
so in the xpac, it seems damage spells will remain scaled like it is now and healing spells will be modified individually. the thing we will need to get used to is now healers will be able to deal reasonable dmg too. as it is now healers get 30% of healing stat as +spell dmg...a fair exchange i think. in the xpac, healers should be able to gear as dps casters do(minus +hit etc). in todays terms that would be like a disc priest having the same dmg as a shadow priest(minus the talents) while still being a high quality healer.
this leads to the talents! it also seems that talents are becoming more powerful and more specific to supplement the previous ideas. it seems even though you will have similar stats, the way these stats are upgraded will be the deciding factor. this will be similar to the way that tanking and melee will be handled(though not as severe). imagine having the same set of gear for healing and dps, only requiring a quick respec to utilize it. great for hybrids!