Asking people to pay for live for windows on top of an xbox live was stupid from the start. Trying to compare that with xbox live itself is silly. I do wonder what the future holds though. Will PSN charge next generation or will M$ make their service free? Who knows. I'm glad PSN is free though, because there's no way i'd pay for two online services just to play KZ2 and mgs online.
And yes, when you're playing single player while online you appear offline to people in your friends list. To be a little fair, this isn't sony's fault directly. Guerilla games did this one purpose for some reason. This may have been changed recently though, as I havn't played KZ2 for about a week. Too many other games have come out recently, it's nuts. Anyways, the fact that sony even allowed them to do something that stupid is the problem though. I doubt that kind of thing has ever happened on the 360.
