I agree that the iPad will not replace a real laptop but it does some things incredibly well like internet, email, games, music, movies, etc. While not perfect, it can work in a pinch for spreadsheets and word documents. Additionally with apps from the app store you can do more neat things. For example I was using a friend's to access the desktop of his work computer and work with our company's MRP software remotely...very cool.
Once you go to an Apple store and start playing with one, you will be hooked. FWIW I heard the iPad 2 will be coming out in March with FaceTime and another IOS4 update.