Do you really think writers are going to get any real work done on an iPad? Because if so, I really disagree. The touch screen simply doesn't lend itself to quick typing and rapid text editing.
Ignoring artists, designers and musicians - since, after all, most people are none of those - and focusing on writing, I think the iPad has a chilling effect. Writing is perhaps the most important activity the average citizen conducts online, so that matters. People kept writing that the iPad is a computer for mothers - my mother, like many others from her generation, was taught to type, a skill that served her well as a legal secretary. She types very well now.
Given an iPad, I expect that although some tasks may be easier for her to accomplish, her lengthy email missives to her children, and her letters to the editor, are going to be much briefer. That's a loss to her family and a loss to civic society.
Of course, none of that matters if you look at the iPad as a toy, a sketchpad, or a device mainly intended to consume media than produce it. But if you believe that it is the "future of computing", as many call it, then this is a problem.
The iPad may well be - and probably is - the future of content consumption, web browsing, gaming, and perhaps television viewing. There's a difference between that though, and the future of computing.