What's interesting, however, is that the entire section was removed, including its header paragraph.
Why remove this entire paragraph, and the section as a whole, rather than simply remove the abilities that weren't in play? It's possible that testing has shown a flaw in this design paradigm - that some particular aspect of the design isn't working as desired. Whatever the reason, however, it does leave us wondering what we're going to see for healers in Warlords? Mana is the 'soft enrage' of a healer - it's as their tanks run empty that fights become unwinnable. They need some method to regenerate mana to keep in the fight. And clearly Celestalon is aware of this, based on today's forum posting.
Another part of the changes to healing is providing a way for them to better manage their mana. There are ways to spend more mana for more healing but we're also adding methods for healers to trade extra time, healing, or more mana to use later in a fight when they really need it.