Great find. My boss, a teacher for the visually impaired, has been talking about trying to order an iPad for our students. Apple is very close to offering a real alternative to JAWS screen readers.
The iPad already has an option to read everything that appears on the screen... it's called VoiceOver... and can be turned on in "Settings." You can set the speed of the voice, whether it uses phonetic pronunciation, key stroke announcing, etc. It's pretty cool. I just tried it. You can also switch the iPad to White on Black display for visually impaired where that might benefit them.