Well after couple of weeks mine is still stuck at 100%. I just haven't managed to move below full?!?! Now I am certainly in the casual category. Also I am loading a bunch of short docs for work (reading at home in the evening) so I keep recharging while copying files.
So apart from you super heavy duty readers I don't think that most users would even notice battery life as we are bound to plug in every few weeks. For me its battery life is amazing and exactly what I expected - one less thing to worry about (unlike for laptops and PDAs).