During the SEGA FES 2018 event, SEGA announced a new retro plug-and-play system called the SEGA Mega Drive Mini (SEGA Genesis Mini).
The SEGA Mega Drive Mini works similarly to the NES Classic Edition and SNES Classic Edition products released by Nintendo in the last 2 years. It is small enough to hold with two hands. SEGA Mega Drive Mini contains an unknown number of SEGA Mega Drive games that SEGA will handpick based on feedback from fans.
More details on the SEGA Mega Drive Mini will be released in the future. The system will be released in 2018 in Japan. No word on a western launch for a SEGA Genesis Mini yet.