• Buzzers - anti-infantry "flying razor blades". Triple-bladed action for smooth, close shave.
• Disintegrator drones - uses short-range cutting torches to disassemble (or disembowel) vehicles.
• "Insect-like" Shock Troopers (hey, is this a Starship Troopers reference?)
• Assimilator - their version of the Engineer
• Mastermind - hey, isn't this thing in Yuri's Revenge? Besides taking over enemy units, this will also teleport friendly units (okay, Yuri didn't have that talent...)
  
• Seeker Tank - fires plasma bursts at tanks and aircraft. Dual-purpose, baby.
• Corrupter - spews liquid Tiberium. The "corrupter" name Mike used might have been indicative of what this thing does.
• Devourer (tank) - guzzles Tiberium. No further elaboration on what else it does, how it attacks, or what it looks like, but the term "guzzles" brings SUVs to mind.
• Annihilator tripod - those three-legged walking orbs of doom you saw in action. In case the vid doesn't work: they also bear a similar resemblance to a walking tower of terror in Half-Life 2.
  
• Devastator warship - aerial artillery for the Scrin
• Planetary assault carrier - you saw this in a screenie, remember? Say it with us: Protoss Carrier. Same principles of operation. Same results on the ground.
  
• Rift generator (superweapon): will create a tear in the fabric of space and time that will warp structures and units into outer space.
  

• The Mothership, a city-sized, slow-moving ship that means "Game Over" for the player whose base it finally manages to reach. You know, like that scene from Independence Day where the aliens blast the crap out of the heart of NYC, LA, and DC with city-sized Frisbees With A Dorsal Fin of Doom. That can't be good.

Via Gamespot