Project Sora is not what many people think, it was just a group of people Sakurai brought in on a contract-basis to make Uprising.
He did the very same thing with Brawl...it was a group of people brought together to make Brawl, and after that game was finished in '08, those people all went back to their prior studios, most likely something Nintendo-related. Sora Ltd is Sakurai's actual company, Project Sora was just a name given to the Uprising team.
Obviously, since Sakurai will be at Namco Studio for the next few years working on Smash Bros, there is no purpose whatsoever to have a team at Sora Ltd. Most people who worked on Uprising will either be absorbed back into one of Nintendo's many first-party studios, while the rest will go with Sakurai to Namco to help him with Smash Bros.
Nintendo should release a statement to clarify this for people, as there is a lot of misinformation going around today about this.
