Judging by the fanboys' negative reaction on here and their
track record of predicting failure, the iPad will be a runaway success.
In all seriousness, this product is perfect for casual use and for students. Just how netbooks aren't fully featured computers, neither is the iPad. My iMac is my central computing hub. Right now I have a MacBook that's my secondary computer and it's too much for what I really use it for - iWork. An iPad is the perfect product for what I need. I can take notes on it, which I can't do with my iPhone, I can read on the way to and from school on the train, and I can run presentations on it.
No, this product isn't for people who want a fully featured computer. But as we all know, full OSes don't translate well to tablets. This is a casual product for a variety of consumers at a great price. It isn't perfect, but that's for future software updates and hardware refreshes to take care of. Just like every other Apple product.
I predict huge success for the iPad.