Here are three must-see resources to add to the conversation:
A Wiki: The iPadschools Wiki. "This wiki is intended to be a clearinghouse of applications, lessons and experiences using the iPad in the classroom. The intention is that all apps listed have been tested and recommended by teachers using them.
A blog post: What is the iPad's Killer App? The App Store. | Cult of Mac
And an infographic:

A Brief History of the iPad Infographic created by a discount codes website
(◕‿◕✿)