it's a computer with the technical term of it. but it CANNOT replace a laptop/desktop. Sure, it does a lot of stuff that a laptop does, but can you import pics/movies from a camera? can you download anything you want from the internet , and open it with your program of preference? can you ... use a mouse on it?
The white mac is the cheapest 13" macbook there is, that's why we need it. Sure I could buy a MBA instead of the macbook, but for the same money i would get a 11", which is too small for me. it's not bad, i have thought about it but i believe it's too small, i like movies etc... which means the minimum price for a 13" macbook is now 1300$ for the air or pro!
ok, connect a usb mouse, a dvd reader/write, a usb camera, an hdmi out and then tell me it's a computer. as someone else mentioned, a toaster is a computer too, but that's not what we usually mean with the word computer..!