Blizzard is teasing new StarCraft II units that will become available in multiplayer when the game’s first expansion, Heart of the Swarm, launches.
Each race will gain more than one new multiplayer unit teases Blizzard, but what they are and what their abilities will be aren't to be revealed until BlizzCon in late October.
The first unit teased is for the human Terran faction. It appears to be heavily armoured. You can see the silhouette of the unit below. Guesses welcome.
A new zerg unit will be teased on the 10th of October, and a new Protoss unit will be teased on the 17th of October.
StarCraft II: Heart of the Swarm has no release date, but it’s likely to arrive sometime next year.