I was looking at that too for a bit until I went on the store

Apple can make the stock of their products disappear pretty quickly, I believe their was something in Steve Jobs biography about this, but I don't remember what it said. Apple didn't give a ******* when everyone complained last year, why would they care this year? They showed it because they wanted to build up anticipation and they wanted people to get adjusted to the idea of a basically non-expandable computer in a trash can that has a lot of thunderbolt 2 ports. And perhaps they wanted computer accessory companies to get their products ready for thunderbolt 2. In the rmbp's case, Apple perhaps also wants to build anticipation for a machine they wanted to release in September, but due to manufacturing/stockpiling parts problems ( IGZO and special Iris Pros

), they had to release at a later date. I don't believe Apple would have even held off the Mac Pro release if they had everything available in time for WWDC. And announcing it before the launch would actually follow in the footsteps of the Mac Pro, both being in Apple's mind "Pro" machines. The time between the announcement and the launch for the rmbp would be a lot smaller, showing that the update will be a lot less significant, all the while keeping inline with the "Pro" factor. It wouldn't be too hard to even just sell of the remaining 15-inch rmbps, since perhaps some people would want the dgpu. They probably planned ahead with the 13-inch, keeping it in relatively low stock for a month, but making sure it is enough to meet the Amazon and other tech retailers"In stock" requirements.