Table of contents

Green means that they have been explicitly confirmed by Blizzard to be in game. Please include an official source.
Orange means that they have not been confirmed by Blizzard, but have been seen in-game. Please include a picture.
Grey means that they have been seen in artwork, or elsewhere, but never in-game. Also have not been confirmed. Please include a link to official Artwork.
Red means that they have been confirmed by Blizzard to not be in the game. Please include an official source.
White means that they or either speculation, and shouldn't be on the list, or that nobody has gotten around to getting a picture of them. The latter applies for the majority.

Blizzard has also announced that all scrapped units, as well as all Starcraft 1 units, will be made available to modders and mappers.

Protoss

Units

Colossus - Confirmed 1
Dark Templar - Confirmed 1
Immortal - Confirmed: 1
Phase Prism - Confirmed: 1 Pictures: 1
Phoenix - Confirmed: 1 Pictures: 1
Stalker - Confirmed 1
Twilight Archon - Confirmed 1
Warp Ray - Confirmed 1
Zealot - Confirmed 1
Carrier - Confirmed 1
Mothership - Confirmed 1
Observer - Confirmed 1
High Templar - Pictures: 1
Probe - Pictures: 1
Reaver - Pictures: 1
Tempest - Pictures: 1
Unknown Unit (Zeratul?) - Pictures: 1
Corsair - Artwork: 1
Dragoon - Artwork: 1
Soul Hunter - Scrapped 1 Pictures: 1
Stasis Orb

Buildings

Gateway - Confirmed: 1
Stargate - Confirmed: 1
Warp Gate (Gateway Upgrade) - Confirmed: 1
Phase Cannon - Pictures: 1
Assimilator
Cybernetics Core
Dark Obelisk
Fleet Beacon
Forge
Nexus
Null Circuit
Photon Cannon
Pylon
Robotics Facility
Robotics Support Bay
Templar Archive
Twilight Council

Heroes

Zeratul - Artwork 1

Terran

Units

Ghost - Confirmed 1
Marine - Confirmed 1
Reaper - Confirmed 1
Viking - Confirmed 1
AH/G-24 Banshee - Confirmed 1
Thor (Must be built by an SCV) - Confirmed 1
Battlecruiser - Confirmed 1
Nomad - Confirmed 1
Crucio Siege Tank - Confirmed 1
Cobra
Dropship
Predator
Medic
SCV

Buildings

Command Center - Confirmed 1
Planetary Fortress (Command Center Upgrade) - Confirmed 1
Surveillance Station (Command Center Upgrade) - Confirmed 1
Sensor Tower - Confirmed 1
Armory
Barracks
Bunker
Deep Space Relay
Engineering Bay
Factory
Merc Haven
Missile Turret
Munitions Depot
Radar Tower (Sensor Tower Upgrade)
Refinery
Shadow Ops
Starbase (Starport Upgrade)
Starport
Supply Depot

Addons

Reactor (Can be added to Barracks, Factory, or Starport)
Tech Lab (Can be added to Barracks, Factory, or Starport)

Heroes

Jim Raynor - Artwork 1
Tychus Findlay - Artwork 1

Zerg

Units

Baneling (Zergling Upgrade)1
Hydralisk
Mutalisk
Nydus Worm
Zergling
Ultralisk

Buildings

None currently Revealed

Heroes

Infested Kerrigan - Artwork 1

Neutral

Resources

Mineral Field - Pictures: 1
Vespene Geyser - Pictures: 1
High Yield Mineral Field - This has been confirmed by Blizzard, but their statement was deleted, along with much of the spam on Battle.net. I'll leave it orange until we have a linkable confirmation. Pictures: 1