Natural units - in other words, units, which don't belong to any sides, but will be available in the campaign, and they can be bought in shops in the skirmish maps.
Some of the new units:
Decapodian cruisers have strong laser cannons, but their most deadly weapon are the close-combat claws.
Reptilon techology hase some strength, like the very durable metal cover, and powerful engines, that make these ships quite fast, despite their big size.
Drakwuf star cruisers
The Drakwuf are a very agressive race, bet known for its weird looking but powerful battleships.
I really like the design of the decapod cruisers! There should be more like them! :p