Thin clients can never replace devices that must be fully functional when a network is unavailable, on a flight for instance. While WiFi is more readily available now than in the past there are still many places and times when it is not. It requires a full computer to provide the connectivity options many mobile users need to get connected.

Small devices are expensive to design, engineer, and manufacture than larger ones such as laptops. This is why we haven't seen such handhelds for less than around $2,000. As processes become more prevalent we will see them come down like everything else. I believe this will happen in 2006.