Valve recently released the Team Fortress 2: Meet The Pyro video, which showed us the world in Pyrovision. Sunshine and rainbows everywhere! And watch Max from Destructoid inflate things...weirdly.
At the end of June, Valve released the Balloonicorn item into Team Fortress 2, which allows players to see in "Pyrovision." Following that, they released a real, actual inflatable Balloonicorn through the Valve store and ThinkGeek.com. We got one in the office, so Max inflated it.