Steam trumps the whole lot of them. Xbox Live's immature community and cost alone make it prohibitive and significantly inferior--yet another reason I can't fathom the console's success in light of the existence of PCs, since online is pretty much its only selling point.
I'm glad to see Nintendo ditching friend codes, as that was a pain, but otherwise, I buy Nintendo consoles for the exclusives, and the exclusives (with notable exceptions SSB and Mario Kart) are single-player. Online just isn't that important. I hope it's manageable and successful enough to help make Nintendo money on their console, but that's about it.
I'm glad Nintendo's offering online free, too. I only got suckered in to paying for Live once and never did it again. I probably wouldn't pay for Nintendo's service either, however good it supposedly is. I suppose the only benefit it would have over Steam would be exclusive games--but even then, how many legendary Nintendo exclusives are multiplayer-heavy?
@Brandikins: While I'm partial to Nintendo, both Nintendo and Microsoft are money-hungry. Their responsibility is to the bottom line, which keeps them lined up with consumer demand. Nintendo's user base is more in line with my interests, which is why I prefer them (and again, I fail to see how the 360 is even marketable), but yeah, they're pretty much money-grubbing. It just so happens that a major part of their success is based on reputation, (arguably) innovation, and strong franchises.