A purported insider leak has now emerged at Blizzard, stating that Hearthstone is a huge success and that Activision Blizzard has low expectations for Heroes of the Storm.
A leak has now appeared, not in some small forum, but on the Yahoo Finance website. However, the text has since been deleted. Tae Kim, the author who wrote about it, claims he considers the source of the leak to be trustworthy, as they had known and mentioned details about Overwatch before the official announcement in November.
Nothing is confirmed here, and this should be taken with the utmost caution.
According to this leak, the following is true for Blizzard Games:
Hearthstone – super successful
Hearthstone continues to exceed Blizzard’s wildest expectations. The game has now surpassed the 75 million mark of players. This is almost 4 times higher than the last reported numbers.
The next expansion is supposed to come in April. Blizzard is working on a 2vs2 mode.

Overwatch: Release 2016, still issues with the business model
For Overwatch, according to the leak, Blizzard has still not agreed on a business model. Players should definitely be able to play it for free, but it still needs to be clarified how exactly they pay for the heroes.
Some in the team had hoped for a release in 2015. However, even if there is a small chance for December 2015, it looks more like a release in early 2016, according to the anonymous source.
World of Warcraft – resolving bottleneck
For World of Warcraft, they have now quadrupled spending on “outsourced art” (i.e., graphics done outside of the studio). This area has hindered certain developments in the past and has been a bottleneck.
The next expansion is “feature-complete.”

Starcraft 2, Diablo 3, Heroes of the Storm
For Heroes of the Storm, they have relatively low expectations. The “higher-ups” at Activision Blizzard expect that they will have to let some of the developers go.
The next Starcraft 2 game is now finished. A release date fluctuates between April and June.
Work on Diablo 3 has largely been halted, and the team is now working on a Warframe-like game in the Starcraft universe with elements from Smite, DayZ, Left4Dead, and MOBAs.
This last statement even triggered one of the rare reactions from Blizzard. They usually don’t comment on rumors and speculation. But they made it clear that the Diablo 3 team continues to work on Diablo 3 and is not planning any “secret project” in the Starcraft universe.
To reiterate: The information in this article is by no means confirmed by Blizzard. The source is anonymous, known only to the author Tae Kim, who seems to trust it.