This strikes me as classic "we can do it, so let's do it" application of technology. I carry a load of books on my phone - but I use them to look up stuff, not for actual reading pleasure. Even having recently replaced my handset with a Sony-Ericson X1, I wouldn't fancy reading more than a few pages. I have a Sony PRS-500 which I think is just about OK for large quantities of text - but I've yet to see a phone with a good enough screen.

I work in a medical school, and we are experimenting with a variety of mobile devices in our course - but while they're OK for looking up dosages, definitions and the like, none have the screen quality for delivery anything more than small amounts of text.