Sega has announced that the next 3 Sonic titles will be exclusive to Nintendo systems. John Cheng, President and COO of Sega America, stated that "Sonic the Hedgehog has proven incredibly successful on Nintendo platforms and we are pleased to continue our long-standing relationship with Nintendo. As we initiate this new exclusive partnership with the next three titles we believe that Wii U(TM) and Nintendo 3DS(TM) are ideal platforms to showcase the evolution of the Sonic brand."
Only the freshly announced Sonic Lost Worlds is known at this time. However, more details on the other games will be announced in the weeks leading up to E3. There seems to be a growing relationship between Sega and Nintendo. First a Yakuza 1+2 port to Wii U, then the exclusive Sonic Lost Worlds, and now this.
E3 can't get here soon enough!