IGN asked if Project Sora had created a "lasting universe" the team could return to in future projects, to which Sakurai replied:
If by ‘lasting universe’ you mean to ask if there's a sequel, the answer is no.
Well, that's fairly cut and dry, then. But why?
Because we pushed a lot into the game in order to let people have this short yet deep experience, but the novelty of that would likely grow thin in the next game. For now, my thought is that perhaps we'll see someone else besides me make another Kid Icarus in another 25 years.
Before you trail off thinking about what a Kid Icarus game in 2037 might look like, remember Sakurai is working on a new Super Smash Bros. for Wii U and 3DS. All better.