Yea, not a chance. Wii Fit will see it's biggest sales in NA, and I think the reason should be apparent.

Obviously not. People will gobble it up.

I think the common consensus initially was that it would suck. Nintendo lost major points with hardcore gamers at E307 when they unveiled it. The true question is whether it will actually be good. Obviously it will sell well, especially since much of the Wii crowd is casual-oriented. But if it actually impresses some of the more hardcore gamers I will be surprised. Of course, I've been surprised by Nintendo several times this generation, so anything can happen.

It'll likely be a big success. There are a lot of people who talk about getting into shape but simply don't want to put any real time, effort, and dedication into it.

It got the media on board instantly, so even if the hardcore turn their noses up at it, the mainstream will be pretty interested.

I'm pretty sure that a number of the hardcore who are looking for something different will pick it up, too.

It might not see a 30% attach ratio like it did in Japan, but would a 10-25%% ratio be so terrible?

It may end up sucking to certain people. In fact, that's kind of a given; there's no such thing as unanimous appeal. I know that I personally look forward to it and believe it'll be quite fun. And I have good reason to suspect that a great deal of people besides myself will too.

how could it not ?

Even if it sucks, it will be widely popular, probably. :P