The Lenovo ThinkPad x230 is available with a good quality IPS display (though still widescreen and low-resolution). I own an x220 with the same IPS display, and I'm very happy with it.
That said, the ultrabook market is still in a weird state. I looked at all of the major vendors and no one really had the ideal combination of components yet. Once you can get the x230 with higher res display and a multi-core CPU, it'll be an ideal machine.
The only ultrabooks I can find with high res screen at the moment are either made by Asus or Sony. I've heard good things about the Asus UX31/32, full HD IPS displays (1920x1080) in a 13.3 inch laptop. A 12 inch laptop with 1600x900 would probably be ideal for me.
[1] http://www.engadget.com/2012/10/02/viewsonics-vx70smh-led-ip...
EDIT-- It probably helps that the MBA has a higher pixel density screen and resolution.