The game is titled Accel World VS Sword Art Online: Millennium Twilight, and it is scheduled for release in 2017.
These official images include screenshots of the characters who will be having big roles in the games, and they are Kuroyukihime and Silver Crow from Accel World and Kirito from Sword Art Online.
It will be an action RPG, much like Bandai Namco’s Sword Art Online games.
Since Accel World happens 20 years after the events of SAO, it seems like the game will be crossing through time.