The Star Alliance website introduces US Airways as the newest member. So I guess its official. However does not mention SAA as a member.
However, Star calls itself an alliance of top, prestigious airlines with reputabe histories, who provide the highest quality of service in the airline industry. I would agree with this, Star is a great alliance of some of the best airlines in the world... so why are they now including US Airways, and airline on the brink of bankruptcy, and according to most A.net opinions, as well as my own, an unfavorable, unstable airline? It seems to me Star would wait to see how US Airways turns out, before it makes it a member. Having US Airways now codesharing with so many Star Alliance airlines, and now having US Airways included in Star's reputation, it would be a public relations nightmare to have one of its airlines file bankruptcy.
I know United is having financial troubles also, but it joined Star back in 1992, long before it had any troubles. So lets not say allowing US Airways to join Star, is no different than United.