Hrmm, I don't know if the comparisons to netbooks is even fair. At UKP199 I think you have to start comparing to full-on notebooks. A regular laptop gets you the keyboard, pointing device, and display, which are all extra with this system. Any base-model Core 2-equipped laptop will be 2-50 times more powerful than a Geode depending on the task. And my powerful ThinkPad consumes at most 24W, including the display, which is comparable to this underpowered matchbox with display. Considering how much more quickly a Core 2 will rip through difficult jobs, the task energy is likely to be superior on a real laptop.
I think their device is cute and has some advantages but I don't think power saving is really among them. If you think about it on an energy instead of power basis I think it's a step backwards.