The Apple iPad would be perfect if it used haptic feedback like the Motorola Droid 2 line of cellphones. Find whoever holds that feedback patent and invest heavily, because they stand to make a killing from licensing it.
Then, again, after some cursory research…Motorola…LOL…Nevermind:
http://www.tomsguide.com/us/motorola-immersion-smartphones-patent-Infringement,news-14141.html
Most likely the patent would just be stolen, and go unnoticed for months or years after manufacturing ceased and the next big push of technology came along to replace it.
As a side note, haptic feedback can actually be overcharged to fatal levels for the user. Best not to put that on an open-sourced platform. Apple fills the bill perfectly.