I've got the Archos 9, and it's too big to easily hold with one hand while using. It comes with an adjustable fold-out kickstand which works great if you've got it on a table or desk, but is useless on your lap.
I believe this issue will be a make-or-break issue for whatever Apple comes up with. If it's not easy to hold while using then people won't use it. If it's not easy to carry around without getting finger/hand prints on the screen then people won't want to carry it around. With a 10" screen it won't fit in any pocket and will be too big to carry clipped to your belt. Perhaps they'll include a nice wide shoulder strap you can clip onto it. 😀