CrunchGear is linking to a Gartner Report that says that mini-notebook (NetBooks or call them what you will) will explode in 2012 with about 50 million units shipped globally by then. Of course that means a lot of ultra-portables will be shipping in the meantime. If that market prediction comes to pass it will certainly be interesting and it will certainly depend on at least a couple of key factors:
3G or better (WiMax?) connectivity will have to get better and become more ubiquitous.
Cloud computing will have to address key issues like syncing, security, and reliability. Certainly there is enough time for those to be addressed in the interim.
Of course four years in tech time is like a century in real time, so who knows what innovations, issues, and developments will happen between now and then.
Now, if we can just figure out what to call the darn things by then.