Updated with additional details from Sega.
Sega's next Sonic the Hedgehog game, Sonic Lost World, will be exclusive to Nintendo Wii U and 3DS. "The onetime rivalry between Mario and Sonic has grown into a friendship that has never been closer," Nintendo of America president Reggie Fils-Aime said in the announcement.
According to Nintendo, this announcement demonstrates "the commitment we have to bringing great games to the Wii U platform." This comes a day after EA officially announced it was not developing games for Nintendo's latest home console.
Sonic Lost World is actually just one of the games part of this deal. Sega later announced that Nintendo's exclusive relationship covers "the next three titles" in the series, and will make Nintendo consoles "the number one destination for Sonic gaming." Additional details are expected in the weeks to come.
"Sonic the Hedgehog has proven incredibly successful on Nintendo platforms and we are pleased to continue our long-standing relationship with Nintendo," Sega of America president John Cheng said in a prepared statement. "As we initiate this new exclusive partnership with the next three titles we believe that Wii U and Nintendo 3DS are ideal platforms to showcase the evolution of the Sonic brand."
While snagging exclusivity for Sonic the Hedgehog makes sense, given the close alignment of Nintendo and Sega's audiences, we're not sure if it's a particularly great sign. You know what system also had a lot of exclusive Sonic games? Dreamcast.