People need to stop dreaming. We already know from simple studies and analysis of past updates and current component market what the next MBA can or cannot be.
What the 13" will be
1. 1.8 Ghz Dual-core ivy5
This is the only processor compatible and relevant according to leaked specs by Intel
2. 4Go memory 1600Hz
Apple is already upgrading RAM from 1333Hz to 1600Hz compatible with Ivy bridge, 8go will only be an option
3. Intel HD 4000
Ivy bridge comes with this new card that is not much more powerful, just more energy efficient. And it's currently impossible to add a GPU to an ultrabook
4.128gb SSD or 256gb SSD if the 15" is released
It's been two generation that the entry Macbook Air 13" has add a 128GB SSD, and because the price as decreased (from 300$ to 500$ for a domestic external 256GB SSD) BUT there are chances Apple calibrates its product line with the 15" so they don't have to upgrade the storage.
5. Two USB 3 ports
It's about time and Ivy bridge is calibrated for usb 3
6. 8 - 10 hours
The battery is probably going to be longer up to 9 - 10 hours but it also depends on other energy consuming component Apple might use like...
(7. Higher resolution screen)
It would seem logical and possible that Apple update it's screen resolution, but because the market is not yet heading in that direction, and Apple has already bumped MBA resolution compared to MBP, it's unlikely
That's about all we can expect. I personaly wish for a 256GB SSD, 4Go Ram is ok, more is better but unlikely, a better Wifi card because it's horrible on Macbooks, HD camera is possible and welcomed AND better graphic performance because I'm tired of not even being able to emulate a Playstation 2 or Gamecube released 10 years ago :/
Then there are crazy ideas, like 3G chip, smaller bezel, lighter material or touch screen, that Apple will never meet because they don't innovate or listen to trendsetters and smart customer anymore.