Actually, you'll only need to buy 2 extra controllers as WiiPlay will be coming with a controller.
I use the have an MSX (well, 2 to be more acurate). I recall they came out some time between the Commodore 64 era and the Amiga era, and at the same time as Amstrad's home computer.
They had a computer keyboard and you could load games using an audio tape player (ah those were the days, waiting 30 minutes or more for a game to load), but they also had a cartridge slot which not only meant fast and reliable loading times, but some cartridges had improved sound chips etc.
MSX was actually a standard, and many manufacturers made MSX machines. Whilst some were very similar, others had specialist hardware. For example, one of my MSX's was made by Yamaha, and it came with a dedicated sound chip and full size music keyboard, with programs for music writing\recording and sound creation.
Obviously, compared to today's machine, the games were quite basic, but a lot of them were quite fun. I'll be looking forward to playing the likes of Antartic Adventure and Pineappling again.
***Edit***
Just looked at that YouTube video and it's reminded my of so many 'great' games on the MSX - Yie Ar Kung-Fu, Knightmare, Comic Bakery, Nemesis, Salamander . . . . .