For where it's designed to fit in, it's interesting. It's obviously not a notebook replacement, and the itouch always seemed too small for video to me. With itunes and an ebook app, it's going to be able to provide a lot of media.
The worst thing about the BB for me is the web browser. So I'd love a supplemental device, but an itouch isn't useful enough, and carrying a laptop around is cumbersome, particularly with the power adapter.
One more generation of this to add a camera and fix bugs and it's a definite maybe.