Isnt a swimming pool just a really big bathtub? Yes technically, but no because they serve different purposes. People buying the iPad get it for different reasons. Some are buying it instead of a netbook. Believe it or not, there are PLENTY of people who have zero need for multiple USB ports, watching flash videos and needing to have 50 programs running at once. They will use their desktop if they need to do that but dont NEED it while out and about.
I bought it mostly for times when I am out and about and want to listen to my music, play games on a badass 10 inch screen, surf the net etc...but I dont want to bring my laptop along and have to sit down to use it. You can walk around and use the iPad, I did it all weekend in San Francisco. Had my headphones plugged in with my iPod going and was online walking down the street and even posting on this forum, try doing that with a laptop or netbook, you cant. Some might be able to on their phone. If you can read whats posted in a forum on your tiny phone screen and then reply on the tiny keyboard as you walk, thats serious talent, I cant be bothered to do that. So for me, its portability and ease of use for when I dont feel like walking around with a laptop that weighs 5 times as much.