I first saw this over in one of FiringSquad's Games that Need Sequels articles. They mentioned it under the Homeworld section. Its not being made by Relic, the people who did Homeworld. Its being made by Bark Dog Studios, the people who did Homeworld Cataclysm, HW's expansion.
As far as I know, Relic, now owned by THQ, doesn't own the rights to HW, Vivendi does. Relic can't actually make another HW game. 🙁
Here's what FS says about it in their article.
"Odds for Revival: Possible. There was a published rumor in Game Informer magazine a few months ago that Relic, now owned by THQ, was trying to buy the Homeworld property rights from its current owner Vivendi Games but there has not been any confirmation of this bit of news. Oddly enough, a development team composed of former Barking Dog members are working on a game called Sword of the Stars that combined turn based strategy with real time 3D space combat. Our view on this is that the Homeworld name and the overall quality of the series itself will become hard to ignore and that a new game in the series will eventually happen. The big question: Will Relic be in charge of its development?"