This could very well be the cause of the delay of the Retina MacBook Pros as I have pointed out a few weeks ago:
1. IGZO displays. These things just faded a little bit in the background rumor-wise - at first glance.
But wait a second: A reason why the release has been delayed is the low supply of display panels (see news post).
Apple has problems with getting the LCD technology which they had time to produce for more than a year now? That simply does not make any sense at all.
What makes considerably more sense is, that Apple will switch to IGZO Displays because they offer superiour quality and incredibly lower power consumption -> providing more battery life and allowing the 13" MBP to become thinner.
The 15.4" displays with IGZO technology are in production by Sharp for just a few weeks. I'd call this a bottleneck right now. It fits very well in the prediction by KGI.