If it wasn’t obvious and/or official before, it is now.
Sonic Team head Takashi Iizuka has confirmed in a Famitsu interview that the team is developing a “completely new game” in store for Sonic’s future.
Famitsu: Finally, our last question – please tell us about Sonic’s future.
Iizuka: We at Sonic Team – are developing a completely new game, as well as developing a full movie, actively done by Sony Pictures, and animation on Sonic Boom. We are also ready to improve sponsor ties.
The most important thing is not the fact the series survived for 25 years, but how many games was developed.
Our goal – add something new and overcome any potential hardships.