What do you mean "hasn't changed any business models"? It has thrown Microsoft for a complete loop. Microsoft has restructured their product development to combat this erosion. Windows 8, Metro, the App Store, etc. are all direct responses to the iPad shifting people away from Redmond's desktop platform.
These are plenty of business that exist solely be use of the iPad/iPhone market. Accessories and apps. And this is quite apart from those business that have been changed. I have watched a radiologist do a consult with someone using an iPad in a car park to view images. That is a change.
