Ars Technica has an overview article about current ereaders and accessibility – the Kindle and the iPad lead and the Nook and Sony aren’t in the running.
We already covered the National Federation of the Blind commending Amazon on the new accessibility features of the 3rd generation Kindle. Here’s what Ars has to day about the iPad:
Similarly, the iPad excels in this area, thanks largely to its sort-of-computer status and Apple’s accessibility support in the OS. Screen reading is not a setting within the iBooks app, but the iPad itself—users can turn on VoiceOver so that every object, menu item, and line of text is read aloud, and the speed of reading can be adjusted to the user’s taste as well as the use of phonetics and pitch changes. When typing (say, if you’re making a note in a book), the device can also read aloud the keyboard characters you’re typing, as well as suggested spelling corrections.