As someone who has a lvl 70 WHM let me give my thoughts quick. I have not had any problems healing, some new dungeons can seem more heal intensive but that was mainly because of either my tank or my own gear was not the best it could be for that dungeon. Some people focus too much on the new mechanics based around cure and cure 2. I think of them as extra, don"t hold back on using certain skills because your waiting for them to have a lower cooldown. The time you wait to use that skill is usually greater than the extra time it would have taken to come off of cooldown. Remember to keep your HoTs up 100% of the time, cast your shield ASAP, and remember to use your healing buffs such as largesse.