The iPad will have its own built-in application for access to books purchased from the ibookstore and in the interface four actions to your library is interesting as well as you can see with the image displayed at the right.  You will have the basic features that you find in the Kindle in the nook, and you get the added bonus of being able to use the iPhone applications that give you access to these two sites as well as other epub applications that are available.  No other device at this moment other than your computer has this capability. So if you are really looking for a new eBook reader the iPad is giving you a reason to take a much closer look at what it can offer you.