The one major justification for MS:
Every game is online atleast in some respects. As far as I know/remember, no Nintendo titles for the Wii (as of yet) are online at all. You pay the $35/USD to get lots of content. Eventually, if Sony played their card(s) right, they'd do a better job, but their at about month 2 vs. MS. MS hit the ground running with the arcade games, and just now, Sony is getting a few good hits.
IMO, its worth the $3 a month it costs.
Back from the dead, I'm afraid.