A business device...
It's most likely valuable to those who have a business need to be on the road all the time, or those that don't need the high end, full featured computing device to accomplish their goal. PCs will not be replaced by these devices because you can't pack the full power of a 3 foot tower into a 4" device. From what I've seen, the video processors aren't getting any smaller, and the dual core high performance architectures are not getting any smaller either.
You need a device for motel hopping on the road, or a device without all the features of a home computing device? This is the optimal solution. Otherwise, I think it would be overzealous to assume that this would saturate the PC market (much like it was overzealous to assume that tablets would replace the household PC).
