Personally, I just don't see the point.  If I want to play a game online, I will just use my PC.  That's why I pay for all the expensive upgrades for it all the time.  I use my console for single player games mostly, and I play multiplayer when I have some friends over.  I cannot possibly think of a console game I might want to play online.  I really appreciate Animal Crossing's online aspect, but I really don't want to see it go further.  It's ok if the option is there, but when it is a required feature, ala FFXI or PSO, I start to get all kinds of warning flags.
The bottom line is that I think that I am not alone on this.  I don't see Nintendo doing anything wrong by not really having any kind of online plan.  If developers want to make some online games, that's fine, and Sega did just that.  I have no intention of ever buying a broadband adaptor, and unless there is a REALLY GOOD (And I am talking INSANELY good) game then I doubt I will ever change my mind.  It's just not worth the extra cost and hassle.  My PC does the job just fine for me, and far better than a console ever could.