I am trying to find out if there is any existing or new research done on Apple iPad personas?
I may have misunderstood your question, but personas are typically based on characteristics and behavioral dimensions that define segments within your user base, not the technology or context in which their anticipated behaviors are analyzed. Persona characteristics should remain consistent across technology and social situations, which is what gives them predictive value, particularly when based on quantitative data. Behavioral variations for different devices, like iPads, are accounted for in usage scenarios.
We've been conducting field studies with iPads to develop new multichannel shopping scenarios to apply to millennial (Gen Y) personas. You can see a video sample of one of these sessions at: http://www.youtube.com/watch?v=HFdo1jKphSQ.
LinkedIn: Digital Design Strategy