I was thinking the easiest way to start the migration from keyboard and mouse interfaces to the touch screen interface is to make it optional. By using a Dashboard type integration to OS X, where you can switch from touch-based interaction to keyboard mouse interaction, at the touch of a button. This will allow users to pick how they interact with the iMac. Keyboard for typing, touch for surfing the web. This would help the development of touch based interface for productivity applications as well as keep keyboard and mouse for large text input situations. What do you think?