The "Machines of War" event for Heroes of The Storm will bring with it two new StarCraft-themed maps.
Last year, a "mini-expansion" for Heroes of The Storm centered around Diablo content, the "Eternal Conflict", brought with it some new maps and heroes. This time, it's StarCraft's time to shine, as Blizzard has unveiled the "Machines of War" StarCraft-themed mini-expansion.
First and probably most importantly, two StarCraft-themed maps will be added. "Braxis Holdout", which takes place on the junkyard planet of Port Scion where terran and zerg forces clash, and "Warhead Junction", which allows players to deal huge amounts of damage with nuclear weapons that spawn across the battleground. These maps are the first StarCraft maps to be added to the game.
Secondly, StarCraft's Alarak, a melee assassin will be added as a new hero, alongside plenty of new StarCraft-themed skins and mounts such as Kerrigan's "Queen of Ghosts" legendary skins.
Finally, while not from the StarCraft universe but still somewhat fitting of the theme, Overwatch's Zayra will be joining Tracer as the second Overwatch hero to be added to the game.
You can read more about the event on the official website. Blizzard hasn't given us any sort of time-frame as to when we can expect the new content, but if it's anything like the Eternal Conflict, various pieces will see staggered release over the next month or so.