So this came across my Twitter feed the other night and it looks kinda interesting. It can play apparently anything. According to that video, this is what it can play:
"Play PlayStation, Saturn, Neo Geo CD, TurboGrafx-CD, Sega CD right on the Base Unit. Expand your compatibility with Element Module Sets for cartridge based systems like NES, SNES, TurboGrafx-16 / PC-Engine, and Genesis / Mega Drive."
http://www.polymega.com/ website is down due to probably preordering so much.