What I meant to write is that, the most logical assumption to come out of this generation is that Mario, like God, is dead.
There were 60M original mario fans. Now, only 8 or 9 million people buy the games that are nintendo staples.
What I think really happened is that all the people who owned NES as children, like me, grew up and have updated tastes that have the same kind of difficulty level/depth as the original NES/SNES. So we have moved to PC or HD systems. The 8 million or so whom buy the "MARIO" games, are diehard fans. All the new fans prefer simpler games.
My point? From this point on, childhood memories will not be made of Mario, but of Wii sports or other games that children's parents decide their children should play. Nostalgia will eventually die, and mario along with it.
EDIT: for example, in exhibit A, it's not that "people buy wii for Nintendo (1st party) games", but that the same 8 million people that buy all the 1st party nintendo games.
EDIT2: on top of that, it isn't shameful to play Mario games. It's just more fun to play things that have an actual storyline. Mario is like Seinfeld without the jokes.