I'm also sure the PC as we know it will disappear or at least change radically, but probably not in the next 10 years. Their mainstream adoption, in the meantime, will probably fall back to the same proportion as people who had PC in the 90's; people who wanted PC because they wanted a PC, not because it became a common household item and a commodity.
Ultimately, I think the trend will go toward wearable computers and perhaps personal household servers when people realize the "cloud" is probably just that: vapor. You will probably end-up with some kind of G modem on your belt, a display/keyboard on your wrist and an earpiece, all connected to your home-server and/or cloud.