Means it needs not only a desktop OS, but desktop performance. Phones are a long way short of that and will be for a long time. You just can't stuff the CPU, GPU, RAM and disk space available in a desktop into that sized box and run it from batteries.

Even the so called desktop-replacement notebooks are still a long way short of what I can get in a desktop.

Don't get me wrong, I'm all for wearable computers, personal area networks and so on, I just don't think they will be a complete replacement for a desktop any time soon.