This report makes it seem like the Haswell rMBP's won't have IGZO. That will apparently have to wait for Broadwell and has nothing to do with the Haswell rMBP delay.
I don't think there is enough IGZO production capacity in place to cover many of Apple's product lines at this time. I would have thought that they would be Mac Book Air first, then Mac Book Pro, all retina or supra retina displays (4K).
Even as small as the iPhone screen is, the volumes necessary would be huge relative to mobile OSX products. This is the downside of Apple's minimalist product line, but I happen to agree with it fully.
4K TB2 screens; just make them easy to calibrate with a wide color gamut.