I don't think people really care about the iPad not being able to make calls; it's not portable enough to be a full-time phone and who's going to want to pay upwards of $40 a month in addition to their regular phone. As for the other stuff, I'm a die hard Apple fanatic, but I can't defend the decision to withhold the camera until version 2, and although I don't care about USB connectivity it seems like something a lot of people do care about.
It may be an iPad killer in terms of features (at least for right now), but, like the Droid and Nexus One, it won't win in terms of sales, and I doubt it'll be close.
EDIT: I suppose it wouldn't cost that much, probably just $10 for an extra line, but I still can't think of a reason it'd be worth it.