Yeah, but those games on there are probably really expensive, no? And do they offer all the games that were for that console?
They aren't cheap, up to £7 per game. But it's rather cool to be able to later upgrade them to the Wii U versions and play on the gamepad. I've never played as many retro games (outside of their original console) as I have since getting the Wii U.
I prefer playing on the original consoles and have been slowly building up my NES and SNES libraries. There's something so good about using the original controllers and consoles, faults and all.