We've mentioned the Sony Reader before, and I think it is going to be released (in the US) soon.
It sounds like it really will make reading onscreen easier, however the £300 price tag will probably prevent it from becoming the 'iPod for text'.
I like it though and I think I'd like to use it when travelling. Visit the Command N podcast #82 and skip to 4 minutes 50 seconds to see it.
Perhaps this sort of thing is going to be important in the future of learning?