It's the Year of the Pegasus! Blizzard released a blog post detailing their year-long celebrations for 10 years of Hearthstone's launch! The blog post details much of the things happening in Hearthstone itself including playing through the entire history of the game and an album full of Hearthstone music.
In addition to this, WoW is receiving a cross-promotion! An in-game event rewarding many Hearthstone-themed items will happen from March 11 to March 18, and players logging in between March 11 and May 14 will receive a free mount.
We have previously datamined the Hearthstone promotion rewards, check them out below!
Logging in between March 11 and May 14 will award players the Fiery Hearthsteed, a red recolor of the original Hearthstone cross-promotion mount, the Hearthsteed.
There will also be a Hearthstone-themed event from March 11 to March 18. It is currently unknown what you can do during the event, besides the blue post mentioning you will need to seek out Hearthstone minions in capital cities and defeat