WPN/DCI/RPGA Stuff:
Here are the current conversions (the first 3 of these were DM rewards for DCI/RPGA DMs in the last three years, the last is the current D&D Encounters adventure):
Village of Hommlet
Tomb of Horrors
Hidden Shrine of Tamoachan
Beyond the Crystal Cave
Wizards has produced faithful adaptations of module T1 
The Village of Hommlet, S1 
Tomb of Horrors, and module C1 
The Hidden Shrine of Tamoachan as DM Reward adventures. They're probably collector's items by now. The last 
D&D Encounters season of the year, written by Steve Townshend, is a wonderful adaptation of module UK1 
Beyond the Crystal Cave, with a few clever twists added.
Next season of D&D Encounters will be titled The Elder Elemental Eye which will tie in with the Heroes of the Elemental Chaos book and the Dungeons & Dragons Fortune Cards: Spiral of Tharizdun. No idea how if it ties into Temple of Elemental Evil or is its own thing.
Dungeon Magazine:
Giant Series G1-G3 converted for 4e by Chris Perkins:
Dungeons & Dragons Roleplaying Game Official Home Page - Article (Big Shoes To Fill)
There will be an additional dungeon involving the Stone Giants that bridges G1 and G2. He has no plans on converting the D series but is interested in doing I3 
Pharaoh or module U1 
The Sinister Secret of Saltmarsh.
Temple of Elemental Evil:
Dungeons & Dragons Roleplaying Game Official Home Page - Article (Dungeon Magazine Sneak Peek)
Another project in the works is a prequel to Gygax’s 
The Temple of Elemental Evil.  In this series of epic-tier adventures, the heroes fight the legendary  Battle of Emredy Meadows, storm the temple at the height of its power,  and try to slaughter or imprison the demonic forces lurking in the  dungeon below. For the first time in the history of 
Dungeons & Dragons,  heroes get to fight the forces of Elemental Evil head-on. We’re also  planning to include options that allow characters from other worlds and  timelines to be drawn into the conflict, giving DMs every reason to  include this epic struggle in their home campaigns.
While this is not a "conversion" it is a prequel to the original T1-4 Temple of Elemental Evil.
I would say sharpen your pitch skills and write up your favorite module for Dungeon.