CNET are reporting that the 13.3-inch Retina MacBook Pro displays have gone into production, with NPD DisplaySearch analyst, Richard Shim, telling the site "The supply chain indications are that it's for a MacBook Pro 13.3 -- not a MacBook Air".

Shim continues to reveal that the displays are being made by Samsung, LGD and Sharp. He also reveals that the launch supplies for the 13-inch model will be much better than the 15-inch model, which goes to show just how popular the 13-inch MBP really is. Shim continues "with the 15.4 it's production of a few hundred thousand units versus one or two million for the 13.3".

So, we're looking at a considerable jump in stock, and I think this model will be the one that really dukes it out with the Ultrabooks. It'll be interesting to see what resolution the 13.3-inch model ends up getting.