Design = function. The reason why the iPad doesn't use a rubberized coating and also the reason why it isn't texturized is because it wouldn't serve any purpose. Apple always uses minimalist design but everything they do, they do for a reason. The population interested in a rubberized back can attach a skin or use a gelaskin, leatherskin, plastic rubberized case, or whatever they want on the back of the iPad. Keep in mind that a rubberized case for the iPad would also mean going to cheaper materials rather than using premium aluminum/aluminium. It's all about optimizing a quality feel for the product and a quality image for the product.