Nintendo8.com now has all of these games online, right now. They are all Flash based. Up until now you had to download an emulator to play on your Mac, PC, PDA, phone, or other device. Finally, someone took the time to figure out how to do it online, technically and legally.
One of my other all-time favorites, Donkey Kong (not Jr.), is not yet available. Someone please let me know if it ever does get added!