I've been thinking about this since the MW2 server decision and it does seem to be a slight change in attitude recently.
Games like http://www.torchlightgame.com/, http://www.captainforever.com/ seem to be actively engaging its players in making the game but also expecting us to pay them.
We can't make good open-source games because someone has to stop playing them and DESIGN/CODE them! :)
So I think we are seeing something different and not so different,ie We should expect to pay for the games we play but we should expect much more input than the big game makers have been giving us lately. I think torchlight points the way: using opensource tools as much as possible but this leaves the ability to modify the game as much as we want but we should expect to pay for it. I think lately we have been expecting everything for free and as programs require more and more effort we should expect to pay for them. ie, the days of paying once and getting mods and upgrades and new content for free Are Over but I know that if I really enjoy playing a game, I think I would continue to support it. again Im not sure this if very much different then the DLC over 360/PS3 but the the difference would be that we wouldn't be limited to just the gamemaker, ie anyone could make mods with these quasi-open-source games and charge for them if they wanted.
anyway I hope Im making sense, the kids are up too early today