I fall into the group opinion that the answer will be no, people will not want them. The following are my reasons.

The form of an UMPC is not what the general public wants. This has already been demonstrated by the relative failure in sales of tablet PC's to laptops. Since the UMPC design, as I understand it, will not be pocketable, as opposed to a PDA, that means some sort of carrying case will be required. As soon as that is established, I believe that the general preference will be a laptop, whose form already protects the screen and allows a full size keyboard. These last two features I believe are key.

I recently had the chance to examine SONY's new micro PC. It was an a very handsome device. It was also much bulkier than I had expected when I read about it. Now about the screen. These words come to mind: What were they thinking? It was impressive in its clarity and color, however, it was ridiculously small. The fonts were at best uncomfortable to read. I really could not get past this flaw. Putting a full size OS GUI in such a small screen is not going to sell. A different environment is needed for this medium. That is why the PDA works so well.

I also agree with the sentiment that the UMPC does not fill any niche. Time and time again I read about people wanting a converged device to carry. I don't think that the larger UMPC form will replace the cell phone or converged device, if it is even meant to.