With my internet phones and notebooks I have always experienced some kind of heat during heavy usage. This heat rise happens during charging, heavy video usage, or in the case of my first generation MacBook Pro ALL the time (to the point your lap almost gets burned). With the iPad I have not experienced ANY heat coming from it even after streaming hours of straight video content.
Also, everytime I whip it out (ehem, my iPad that is) it gets some attention, maybe because they are impressed with its size (again the iPad). Share your experiences with gawkers when you use your "Magical & Revolutionary iPad" according to Jobs.