I would like the size of the 13" MBA to be similar to the size of the Dell XPS 13 Ultrabook. It's got a 13.3" screen but the body of a 12" laptop, with a footprint that's closer to the 11" MBA.
I agree, but I'd also like a higher resolution. It doesn't necessarily need to be a "Retina Display," but I'd like something a bit higher than 1366x768.
Well the 13" Air already has a resolution of 1440x900. They could go a bit higher, maybe 1080p, but you would probably want some UI scaling at that pixel density to make it usable.