I think you may be begging the question* by expecting a Great Divide, with mobiles on one side and non-mobiles on the other.
Concrete example: In CSS you can make @media rules for "screen" and "handheld". iPad follows the rules for "screen". (I detoured here to re-check. Also established that my iPad considers itself to be 980px wide.)
If you're thinking about display, an iPad is a screen (plenty of real estate, high resolution, reasonable bandwidth). If you're thinking about user interface, an iPad is a mobile (only one type of "mouse" event recognized).
* Assuming for the sake of discussion that everyone reading this knows what "beg the question" means. Hint: It does NOT mean "forcibly raise the question".