Possible interpretation of the riddle . . .
What if the iWalk / iNewton is a pen based, airport equiped super_digital assistant that wirelessly can control any Airport-based Mac within range? No need to port software to some scaled-down, OS X Lite (talk about frustrating the developers!); apps would be run in native mode, from the host computer when connected to Airport. Apps for the iNewt whenever it's a standalone, out-of-basestation range PDA would include MP3 playback (though it would compete with the iPod in this area), Quicktime content (flash, Mpeg4, MooV, etc.), Notepad and other regular_PDA-ish functions.
Any thoughts? it would almost act as a pen-based remote control (such as Timbuktu) for desk-based systems. I'm not sure the advantage this would have over a laptop (portability, obviously), but this is definitely where no PC has gone before.
Comments and logic are welcomed . . .