New titles from original Xbox are now available to play on Xbox 360 via Xbox Live Autoupdate. Just insert game, have fun.

Title Name Notes
America’s Army
Auto Modellista
Bass Pro Shops Trophy Hunter 2007
Blinx 2
Bloodrayne 2
Burnout
Crash Bandicoot 4
Crash Bandicoot 5: Wrath of Cortex
Doom 3: Resurrection of Evil
Drive to Survive
Drive to Survive (EM)
ESPN College Hoops
ESPN NHL 2K5
Evil Dead Regeneration
Exaskeleton Japan only
FIFA Street 2
Full Spectrum Warrior: 10 Hammers
GUILTY GEAR XX #RELOAD
Harry Potter: And the Chamber of Secrets
Harry Potter: And the Prisoner of Azkaban
Hot Wheels: Stunt Track Challenge
Jet Set Radio Future Updated
Justice League: Heroes
King Arthur
Kingdom Under Fire: The Crusaders No Live Access
Magic: The Gathering: Battlegrounds
Marvel Nemesis: Rise of the Imperfects
Marvel vs. Capcom 2
Mech Assault 2
MLB Slug Fest 2003
Morrowind
MotoGP2
Myst III: Exile
NBA Live 2002
NCAA Football 06
Nobunaga no Yabou Ranseiki Japan only
Outlaw Golf 9 More Holes of X-mas
Outlaw Volleyball: Red Hot
Outrun 2
Outrun 2006: Coast to Coast
Pac Man World 3
Panzer Elite Action: Fields of Glory EMEA only
Pro Cast Sports Fishing
Project Gotham Racing
Project Gotham Racing 2
RoadKill No Live Access
Rogue Ops Updated
Sega GT 2002 Updated
Sega GT Online
Shadow Ops
Showdown: Legends of Wrestling
Silent Hill 2: Dreams US/EMEA only
Sponge Bob Square Pants: Lights, Camera, Pants!
Teenage Mutant Ninja Turtles: Mutant Melee
The DaVinci Code
The Sims 2
The Urbz: Sims in the City
Tony Hawk’s Pro Skater 2X
Tony Hawk’s Pro Skater 3
Transworld Surf
Trivial Pursuit Unhinged
Winning Eleven 8
Without Warning
WWE Raw
Yu-Gi-Oh! The Dawn of Destiny

Glad to see they’re still at work on this, I thought they had given up on it.

Source - July 2007 Back Compat Update