I actually took a crack at predicting the expansion's contents, just prior to the Wrath launch. At the time, I accepted Tobold's unexciting prediction that the expansion would contain a healing-based hero class. After all, healers and tanks are the two hard roles to fill, and this expansion added a tank. It appears that we may have been incorrect.
More Niches Than Classes?
The former WoW Insider links to an interesting interview with WoW (the game, not the now confusingly-named news site) Producer Tom Chilton. Though he confirms nothing, in true Blizzard fashion, he does state:
"...we don't feel that we can support the pace of adding a new class with every single expansion."
Looking back, this makes a fair amount of sense. WoW now has four tanking-capable classes, four healing-capable classes, and four classes that cannot do anything besides DPS. (Those numbers add up to twelve instead of ten because Pallies and Druids can both tank AND heal.) Breaking it down by talent trees, we have five healing trees, six tanking trees, and twenty three trees that can be used for dps (including feral druids and the three DK specs, which can also be used for tanking, for a total of 34 instead of 30.) Carving out a niche for each of those variations is a tall order that Blizzard is struggling with at the moment.
Eight months ago, I thought that the need for more people willing to heal outweighed those difficulties. Now, I'm less convinced.
Do more healing classes mean more healers?
Blizzard made a decision to design the Death Knight with three trees that could BOTH tank AND DPS, in the hopes that this flexibility would encourage them to tank as needed. In practice, the way the game is set up strongly favors players making up their minds which role they intend to pursue and sticking with it. As I noted at the time, you can get players to roll as a new tanking capable class by making a shiny new class, but that does not necessarily convince them to become tanks. The hypothetical Arch-Druid/Warden healer hero class, with three trees that can both DPS and heal, would have suffered largely the same fate.
Instead, Blizzard decided to go with dual specs so that current players of healing-capable classes could learn to do so. Though I don't have statistics to back this up, it does seem like finding a healer for a PUG (if not necessarily a great healer) has gotten much easier since patch 3.1. This solution is not necessarily ideal, as it blurs character identity. Then again, as Spinks observes, adding more and more tanking class options don't necessarily help find the tanks raid slots. That may be just as important a factor as the actual merit of the classes in question.
So What's Left for the Cataclysm?
The Chilton interview claims that there is a fair amount of ground left to cover, but chooses to mention only the two long-time front runners - the South Seas Islands with the Maelstrom, and the Emerald Dream. He also notes that they feel that new playable races should be races that have been seen in WoW before, rather than dropping Draenai in with no warning from Outer Space. Though he does suggest that BWL Drakenoids would be a cool player race - which would fit nicely with my Clash of the Dragonflights idea for an expansion - I'm not sure that making those guys playable would actually seem any less out of left field.
Perhaps Blizzard still would favor new races, with the opportunity to add in some new scattered content settlements in the 20-60 range to flesh out the new backstory. Or perhaps we're looking at a new expansion with neither new races (Blizzard does not seem inclined to use neutral races, so they would have to add two at once) nor new classes. If that's true, though, there will be extra pressure on Blizzard to deliver something that really makes players sit up and notice, if they don't want their expansion announcement - 10 new levels and what else? - to be a big disappointment.