From the makers of Homeworld: Cataclysm, to be specific. (Former Barking Dogs Studios iirc)

GCII and SotS focus on rather different things - SotS seems to be more focused on the "space opera" factor of having lots of large capital ships blasting each other apart and looking good while doing it, and incorporating a visually appealing, simple inferface.

GCII will probably end up being the more cerebral game - more focus on strategy, diplomacy and especially colony management.

SotS might be well suited for multiplayer, since the campaign mode appears to be simple and battles somewhat faster than in Homeworld. If I understood correctly, there are also techs to spectate others' battles, so that should help eliminate boredom while others are duking it out.