I'd consider...
I've been saving pennies for a 20GB iPod (and have been waiting for the next revision, really) but would consider the 40GB, assuming it would be the same price as today's 20GB.
Reasons? I can put important files, or even non-important ones, there, and not worry about the 11GB music library being affected. That would be a fantastic bonus, and I'm sure that Apple is thinking along those lines too.
"It holds your music, your contacts, your appointments, your social security num..." oops!
- Paul