Most of them are arcade games, with a few notable exceptions like Halo: Reach and Fable III.
That’s fine, though, because some of those arcade titles are classics and they’re also most likely to be in a lot of Xbox 360 gamer’s accounts already.
There are a lot more games being prepared for backward compatibility, plus all of those that have already been added; Fallout 3, Gears of War 3, Just Cause 2, Assassin’s Creed II and DiRT 3.
(list taken from Major Nelson's blog)
|CONTENT TITLE||CONTENT TYPE||PUBLISHER||STATUS|
|DEUS EX: HUMAN REVOLUTION||Games On Demand||SQUARE ENIX||NEW|
|Doritos Crash Course||Arcade||Microsoft Studios||NEW|
|Fable III||Games On Demand||Microsoft Game Studios||NEW|
|Halo: Reach||Games On Demand||Microsoft Game Studios||NEW|
|Hydro Thunder||Arcade||Microsoft Studios||NEW|
|Iron Brigade||Arcade||Microsoft Studios||NEW|
|Kane & Lynch 2||Games On Demand||Square Enix Ltd||NEW|
|Motocross Madness||Arcade||Microsoft Studios||NEW|
|MS. PAC-MAN||Arcade||BANDAI NAMCO Entertainment Inc.||NEW|
|Peggle||Arcade||PopCap Games, Inc.||NEW|
|Portal: Still Alive||Arcade||Microsoft Studios||NEW|
|Splosion Man||Arcade||Microsoft Studios||NEW|
|Ticket to Ride||Arcade||Microsoft Studios||NEW|
|Zuma’s Revenge!||Arcade||PopCap Games||NEW|