You might remember when Diablo III screenshots were first making the rounds, and the Internet had a bit of a collective freak-out over all the pretty colors. The game's producer urged calm, but apparently the team opted to have a bit of fun at the expense of the controversy. Players are discovering a secret level called Whimsyshire, and it's amazing.
A Blizzard forum post details how to find the secret area. If you collect a set of items from various acts, and a set of plans from Izual in Act 4, you can open the portal leading to the stage.
Finding it grants you a Feat of Strength and Banner Sigil, but the real gift is the hilarity. Check out a video below to see it in all its sparkly glory.