I've heard that the insides actually contain an ARM CPU emulating a MD/Genesis (not unlike what's inside Nintendo's offering), plus additional hardware to convert the mapping of physical cartridges to a filesystem compatible with the emulator. Not really that great given that this means that peripherals like the Sega/Mega CD and 32x won't work.
Honestly, I'd prefer pulling my old MD clone out of the closet and use that instead.
Interestingly, NXP still does make 68000 CPUs, as does Zilog with the z80. Wonder if the remaining PSG and YM OPN is still being produced, because apparently, the heart(s) of the Genesis is still readily available off the shelf.