Sakurai states that Kid Icarus: Uprising is top priority.
http://www.nintendoworldreport.com/news/27917
The next game in the Smash Bros series won't begin development until Kid Icarus: Uprising is finished, said Masahiro Sakurai in a Twitter post.
The head of Project Sora stated on his Twitter account that "I'm currently concentrating on one title, Kid Icarus. Until this wraps up, Smash Bros. will not progress. Of course, characters have not been decided at all."
Recently at the Nintendo 3DS Press Conference, it was announced that Kid Icarus: Uprising received a delay. It will now be released sometime in 2012. The new Smash Bros game was announced for both the Wii U and the 3DS.
I wonder if little part of Sakurai died when they surprised him with the Smash Brothers announcment at E3...
They started development?
More than anything though, I want real alternate costumes... like Wario had. Sonic should also be Shadow, Silver, and Metal Sonic. Snake should be Solid, Liquid, and Naked. Mario should have Dr. Mario, Link should have Toon Link, etc. If nothing else, it'd be nice to see 8 or 16 bit costumes for a lot of the roster.