Exact information is not yet available. Sega has several announced projects that have not yet been shown to the public: reboots of the classic series Crazy Taxi, Golden Axe, and Jet Set Radio, a new version of Virtua Fighter 6, and a possible new 3D Sonic platformer — the series has not had such games for three years, and next year it celebrates its 35th anniversary.
Previously, companies tried to keep participation a secret, but in recent years they have more often warned fans about their plans to avoid leaks. What exactly Sega will show is still unknown.