[quote name='daroga']I'm not a big fan of the Mario Party games, but I can't see how online would help this. Mario Party is a party game, meant to be played with other people in the room. I don't see a game like MP being any different when played online as opposed to playing against the computer.[/quote]
That is probably Nintendo's viewpoint, but I think you could argue that pretty much any multiplayer game is better when you are playing the in the same room. That doesn't mean it wouldn't be nice to have an online alternative. If you have ever played Mario Party against the computer, you know how painful that experience is. Playing against another human, even online, would have to be better.
Plenty of games that are traditionally played in the same room are moving into the online realm. Online poker, cards, boardgames, etc., are all common and pretty popular. Hell, XBLA just got Catan recently.
My wife and I typically play Mario Party games with my in-laws. Now that we have a toddler, it's a lot harder to get together to play MP like we used to. Being able to play them online (and other friends and CAGs as well) would be a nice addition.