If I were to be able to choose any feature of the new MBA this is what I would choose as my number one request. I highly doubt we will see this happen but I sure would be willing to pay a lot of money for an advanced display like this.
I can hope and dream, can't I?
I feel that an IPS display is likely. However, I wouldn't rule out OLED for the MBA, especially if it's an 11.6" display. With Apple's partnership deal with LG, you know handing over $1b advance for displays over the next three years, I believe OLED is even possible. I also think 3D is an extremely remote possibility, but Apple would have to see a way to integrate software into making it a cool Mac feature... doubtful.
I have been saying for a year I believe Apple would introduce a new display technology in the MBA first. With Apple also making the retina display for the iPhone 4, it shows us that Apple can focus on a better experience through the display. We do two things with our Macs all the time... we look at them, and we do input via trackpads and keyboards. The MBA has a great keyboard and will probably have the large glass trackpad soon too, so why not improve the only other feature that we use ALL of the time.
Some people also complain about a high resolution display, but Apple can even set a lower resolution as the default in the settings. People that make this complaint that they couldn't see 1440 x 900 on a 13" display are making a horrific argument... as they can always lower the resolution in less than ten seconds. I think this is another way to improve the MBAs by giving us the CHOICE to have a more desktop workspace within the same 13" display.