A photo from a toy fair held in Nuremberg suggests that Sega's blazing-fast mascot will make his way to the next-gen consoles in 2015. Spindash's report, as translated by Sonic Stadium, notes a placard at the event from toy manufacturer Jazwares that hints at a Sonic game for the PS4, Xbox One and Wii U. Jazwares currently has a line of Sonic merchandise, so it would make sense for them to know about future Sonic projects.
The image notes recent Sonic games in addition to the "new 2015 title TBA" game, but it doesn't make note of Nintendo's "worldwide partnership" with Sega to release three exclusive Sonic games on Nintendo platforms. Sonic: Lost World kicked off this supposed trilogy and Mario & Sonic at the Sochi 2014 Winter Games served as the second installment, so it's unclear whether the TBA game used to be Wii U exclusive, or if another Sonic game is still in the works for Nintendo platforms.