Wow. I totally didn't know that. Maybe in a few years when I have the spare cash, I'll get into more of the mid-era Sega systems and try to give this a shot, just to say I did it once.
It'd be nice if more systems would do this, but alas.. I remember being rather sad at the X-Box version of Live finally going down for good recently, and thinking of all the games that would never be played online again(or played multiplayer period, in some cases.)