I posted the exact quote. And it goes as follows.
"We have entered into a worldwide partnership with Sega on the Sonic Franchise."
What this partnership entails wasn't given, but it was obvious it wasn't just for one game. And if you look at Nintendo's last partnership for a title Nintendo is developing the title along with the developer. (FE X SMT, Atlas and Information Systems are developing the title.) So it a safe bet to say that Nintendo is lending a helping hand with the title.
It's 4:12-to-4:30 on the video here.
http://www.nintendo.com/nintendo-direct/archive/05-17-2013/#/video-ndirect







