Well, pre-ordering of the WWDC MartianCraft T-Shirts for 2012 is now closed. We're going to leave the order form up until WWDC ends and do one final print run at that point. After that, the 2012 shirt is going out of production. We'll be back next year (or maybe even sooner) with a new design, but this particular one will be retired for good.
As I mentioned before, we will be bringing some shirts with us just like in past years, but we're not promising them to people an advance. There's too many people who'd like them. It's too hard to keep track of who was promised what size and we end up carrying dozens of shirts all over the place looking for people. When we have shirts available for givesies, either Rob or I will tweet where we are or how you can get one.