Here is an inspiring story and video from The New York Times about a boy with a degenerative disease that has been able to interact with an iPad. His mother says it is the first device that they have had success with and it is far cheaper than other devices they have tried. In addition, because the apps are inexpensive they can experiment to see which ones are the most beneficial.
The article notes that there are studies in progress to determine how effective the iPad is for people with disabilities. In the months since the iPad has been on the market, it has already become a popular device for assisting the disabled but the usefulness of the device depends on the specific disability. In the coming months, we can expect that additional apps will be created and added to the app store to assist disabled users.