Aside from the obvious, faster processors, larger capacity for data storage, improved resolution, I think the future of the iPad will be:
1) a device that helps usher in more tablet devices, electronic textbooks in classes, help the publishing industry and see that tablets aren't a replacement for computers but a new tool that requires a new change of thought.
2) a device to showcase some new perhaps mind-blowing technology from Apple. Apple has been applying for patents, like madmen for several years now, some of them pretty crazy stuff. They've been researching LCD that has sensors (see this
article form 2008), that can act as a large camera, and also make it so that programs are aware of the user via the sensors. I forget the article, but there was another one that talked to some researchers where they said these LCD sensor technology could improve the feeling of immersion into a game world drastically, as the game could sense where you looking at react accordingly, like game-world characters noticing if you where looking at them or somewhere else, etc.
Some of these sensor technology has evolved recently into different uses as discussed
here where Apple recently won a "proximity field sensing" patent, that senses a finger's location off the screen, allowing for more user control, like lets say your finger is no longer hovering over a button (not touching the screen, but just hovering), the button will know that your finger is not near and remove itself from the screen.
They also put in motion detector/accelerometer technology in an
experimental headset.
Just like the accelerometer and the multi-touch screen advances moved from fantasy to fiction, Apple will most likely include more stuff into the iPad that we can't fathom yet.
