Boy, this is pretty interesting. Basically you open Chrome to this website, and you can stream any SNES game in a room. The controls are also streamed, and anyone can join in with the same controls. Best way I can describe this is that it's like the online SNES version of the GBA or DS's single cart multiplayer function. Only weakness is that there may or may not be some lag, but given how you're playing that's just expected.
There's an NES version too. Anyone tried this?