My iPad 2 lasts all day. The only thing that really kills it is watching web based videos like Netflix and Youtube - but even then I get most of the day. I use mine all day all the time and I haven't really seen any degrade in battery life - even with quite a few charge/discharge cycles.

What didn't last too long for me was the smart cover. I started getting a tear in the flap that holds it to the metal. It started sliding - and now it slides all over. Luckily you can get replacement smart covers on sale from Amazon.