Eric Dodds, the lead designer working on Hearthstone, says that at the moment the Druid class is being used by most of the high-level players, but the game’s dynamic nature means that the situation might change very quickly.
He tells Eurogamer that, “Right now there's a lot of Druids at a high level, but there's been a swing of other classes - people finding out how to beat that deck. Even now they seem to be on the downward swing and losing that top status.”
The Druid class has access to a lot of spells and also gets a boost to mana, which appeals to a high number of players.
Hearthstone is a card-driven experience that uses a variety of magic attacks and units drawn from the World of Warcraft universe.
Blizzard plans to expand it with a new Adventure mode and might add more classes in the future.