I know emulation makes this device unnecessary, but sometimes you want to play with genuine controllers and a real cartridge. I feel clone consoles that slot into a desktop PC like an optical DVD-R drive would be coveted by a few gamers out there.
Most PC towers have several drive slots in the front, may as well populate them with clone consoles! Cartridge-based clone consoles would look similar to the above example. Disc-based systems would have a DVD tray and compatible control ports. I don’t think memory card slots (GameCube, PS2) are needed.
There is the Retrode device, which has cartridge slots for the SNES and Genesis, and plugs into the PC via USB. It’s a great device and is portable, but I would prefer something that is integrated, given the choice.