For a reader, a large screen without a keyboard makes a lot of sense. For a communicator, a small(ish) screen and a keyboard are mighty useful.

I'm pretty sure that in the future we will all carry electronic reading devices in our bags (rather than books), and communicators in our pockets. Perhaps a "workstation" (aka netbook) in our backpack. I'd like to see free software running on all of them. Maemo and moblin are forging ahead by focusing on specific use cases.