For many individuals, gadgets like tablet PCs and netbooks are secondary devices. We may rely on a "heavy duty" desktop at home or in the office. We may even have a robust laptop/notebook that we use as our main machine. Then, we may carry a netbook, an ultra-mobile PC, or a small tablet as a secondary device.
For me, my Samsung Q1 Ultra UMPC is my office "note pad." I try to avoid using paper whenever I can. So, I'm using Microsoft OneNote to take my notes during meetings. I'm constantly connected and I'm able to quickly look things up on a web browser. For these types of secondary devices, we really don't need to run a full operating system. Instead, a slimmed-down version or even a simple Linux OS is often quite sufficient. I think Lenovo has the right idea with their Skylight 10" mobile computer. Some are calling this a netbook, but this is somewhere between a netbook and a smartphone. It will be interesting to see how these secondary devices evolve as users recognize that they need for a robust solution at home and in the office and they don't need such a robust solution for a secondary device.