I think you could transfer files between computer and IOS device if the IOS software is programed for that type of feature. The crutch with the IOS devices is you need to use itunes to transfer any files between IOS and computer. I'm sure there may be other ways but that is how all programs that I have handle file transfer.
Is it as easy as say network browsing or using a memory card, no.
Is it that big of a pain in the ass, no.
I'm sure we all would like to just find the IOS device and transfer it and it's just there, maybe a new feature in the new new iPad and IOS 6.5
I didn't think about the interfacing aspect of the surface that was brought up before. In some aspects the touch screen and gesture could just be handled by the OS and the application only see's the interface like a mouse click etc.. We have a few touch screen computers for machine interfaces and they all have software features that handle that function, but do it poorly in comparison to using a Android or IOS device where it is a major part of the experience.