The special WWDC 2012 edition 5by5 T-Shirts have shipped. From my post on the 5by5 blog:
Our friends at Amplifier just told me that the special WWDC 2012 edition T-Shirts have all shipped out. Most made it out the door from their Austin, TX facility on Monday 4 June, 2012. This means that many of you will receive your shirts in today's mail.