My friend bought a laptop 5 years ago that you could turn the screen around completely, refold and use with a pen like a proper notebook (and no it wasn't a mac). Already been done. Of course, with Apples new budget from ipod revenue they will try all sorts of stuff. The vast majority of which will just be old ideas with new iwrappings.
Don't forget that blogging is extremely important as a kind of agenda of sorts. Most people havn't been using the internet long enough to realise this but 20 years from now, they will be able to go and seach for stuff they blogged about and they will have a sort of album online of part of their life they can go back and look at. I think many people will realise how important it was to blog just so they can go back and see how their lives have changed, how the world has changed and many other things.