Based on what info I know now, these are my guesses:

- A6 processor (whatever it's specs may be): 100%
- Same design (not thinner, maybe lighter): 95% (This design
just works)
- Bluetooth 4.0: 85% (imagine it's possibilities, seeing to what iPad is being used already today in medical industries)
- Retina display: 65% (Since the production problems, it may not appear just yet)
- Better camera/microphone: 60%
- Siri: 50% (Siri IS useful for mobile devices, but I believe it's more useful on iPhones than on iPads ... Who knows, maybe Apple thinks the same about that

Maybe not; Siri is a great marketing object for Apple.)
- More RAM (1GB): 40% (iPad2's 512MB does quite a decent job, why would Apple change it? Maybe for more memory intensive games or high end production apps, otherwise it doesn't make a whole lot of sense.)
- More graphical performance: 20% (due to its huge increase with the iPad2, I don't expect any real exciting changes here)
- Smaller version (7")/ "iPad mini": 0% (i would rather see it like a large iPhone rather than a small iPad ...)
Might have missed quite a bit, but it's obviously just a guess
