I'm going to sound like a broken record here, but if you check out the emulation thread we've detailed how to use a raspberry pi to make an emulation station for your TV that can play all the games from the 32-bit and lower era. Whenever we have people over it's like nostalgic overload - no matter what we were doing everyone gets sucked in trying to beat the water level on TMNT for NES.
To me making a cartridge based system is just a shitty money grab. It's outdated technology that they're hoping will get some old dudes chasing nostalgia to buy.
BTW, my brother bought my dad one of those Sega Genesis 'retro gaming systems' that you see at like Target and Walgreens and it is a piece of shit. The controllers are awful and you can't even save games.