Nobody wants to use a mouse or a trackpad.
Sure, that's what we've gotten used to because of the limitations of technology but the ideal has always been the direct manipulation of objects with your fingers. That was always the next evolutionary step and the iPhone, with its wonderful multi-touch capacitive screen, was the first one to get it right.
The touch screen IS what makes the iPhone so enjoyable to use. When I'm already on my laptop, I still prefer to use my iPhone for certain apps: Fandango, Calculator, Stocks, iTunes, Mail, Mint.com, MyWireless, Zagat, Pandora, Skype (for voice calls) and most games.
When Jobs says the iPad has a better experience than a laptop, I believe him because the iPhone is already better at many tasks. The problem is obviously the small display. Tasks with a lot of reading are still more enjoyable on a laptop. Well, the iPad has all of the iPhone's strengths and solves its main problem.
While the iPad doesn't have 100% of the functionality of a laptop, I strongly believe that a lot of people can survive with the iPad being their only PC. Most people spend 90% of their time inside a web browser: surfing the web, checking e-mail, social networking. Other times, they might play the occasional game, write a paper/letter in Pages, check calendar or address book, or IM with friends.
They can do all of this with iPad, a product that is:
1. More intuitive, easier, and enjoyable to use than all other laptops.
2. Lighter and Thinner than all other laptops.
3. Half the price of the next cheapest Apple portable computer (MacBook)
I would even go as far as to say that the iPad is the first full internet device anyone can use. As easy as mice/trackpads are, you must still learn how to use them but anyone can pick up an iPad and browse the web in minutes. No one needs to be taught how to use an ATM.
As far as the keyboard is concerned, I type about 80WPM and 40WPM on the iPhone. If the iPad can give me 60WPM, that's good enough. Keep in mind also that most non-tech people "hunt and peck" anyway so it'll all be the same to them.
This is Apple's most important product because it's the first full computer for everyone, from 3-year-olds to grandmas and offers a browsing experience better than even the most expensive of laptops and does all that for a price point of $499.
My prediction: iPad will be the most successful product in Apple's history.