Dedralie at Healiocentric has started a series examining how the 6 healer specs fared in Mists of Pandaria, and the first installment starts with a look at representation in raids. It's a fascinating article on the rise, fall, and sometimes stagnation of class fortunes, and toward the end there's a pretty cogent prediction on what mythic raids in Warlords of Draenor are probably going to look like if current trends continue.
This is a quick summary, but I'll provide more details past the cut. As Dedralie writes, while we're not really talking about healer balance or throughput here, there are a few obvious trends you can track from the Mists launch in September 2012 all the way to heroic Garrosh kills in January 2014:
- Discipline priests and holy paladins ruled the expansion.
- The absorption effects brought by these two healers is a huge advantage in heroic content (even more so in 10-man), and it may be too valuable as a mechanic.
- Tier 15 (Throne of Thunder) was the most balanced with respect to representation. Tier 14 saw significant gulfs between class popularity that unfortunately returned with a vengeance in Tier 16 (Siege of Orgrimmar).
- While monks and holy priests are still struggling for representation, it's instructive to look at the fights where they were significantly more popular.
- Mythics will probably look like the "under-healed" heroics of MoP, which will prejudice heal teams toward synergies between absorption healers and those with strong throughput-based cooldowns.