Wizards of the Coast has launched a new organized play event in participating stores, called D&D Lair Assault: Into the Pit of Madness.  The event runs through May 31st. 
Into the Pit of Madness presents the "Forgotten Temple of Tharizdun," home to a cult determined to free the evil "Chained God."  This adventure was inspired by Gary Gygax’s The Forgotten Temple of Tharizdun and The Lost Caverns of Tsojcanth and Monte Cook’s Return to the Temple of Elemental Evil.
The adventure is intended to require only a few hours to play and encourages players to play more than once.  Lair Assault events are designed to present situations that challenge the players’ knowledge of the Dungeons & Dragons rules as well as their tactical decision-making.  Players create their own characters, drawing from any official Wizards 4th Edition products.  Into the Pit of Madness allows 10th level characters.  Participants in the event can earn "glory points" that can be redeemed for profile badges on the Wizards Community website.
The Lair Assault events are run parallel to the D&D Encounters events, but are not related to them. Wizards has recently allowed participants in those events to begin using the D&D Next ruleset (see "'D&D Next' for 'D&D Encounters'").