I'm a long way off wishing all my books were electronic. And it depends on the type of book as to where my preferences lie. I've said before that the typesetting and presentation of most e-books is rubbish - not to mention the e-readers, the software and the formats (e.g. EPUB, Mobi) being barely up to the task. E-books are at their shaky best when the source material has no footnotes or images or tables or non-standard fonts or unusual layouts. Nevertheless, I'm reading more and more books electronically. And when I switch back to paper I'm starting to notice a few failings by comparison:
* Reading in bed the other night I actually caught myself thinking, "I'll put the light out now and just read one more chapter." Then I remembered I was reading on paper not on my iPad and paper needs a separate light source.
* I've got pretty used to asking a book to define a word like 'metonym' or look up a term like 'Hanseatic League'.
* It's not ideal, but every now and again I want to read a bit more of the book I was reading at home while I'm on a train... and all I have with me is my phone.
* If I'm looking to quote something I read, I like to be able to search a book
* I'm on a trip and I get two pages into reading my book and realise I want to be reading something else. I like to be able to either dip into one of the other fifteen books I've got on the go (not novels, of course. more likely to be things like Gleick's The Information where you can read a chapter at a time). Or I'll nip online and buy something new.

That's not to say that paper books don't retain a lot of advantages - and they're put together with much more care too - but it's got to the stage where I feel they also have their drawbacks.