Maniacal
the green Napoleon
http://forums.totalwar.com/showthre...-Total-War-multiplayer-now-available-on-Steam!
http://forums.totalwar.com/showthread.php/132205
tl;dr
Medieval 2 and Rome have been updated on Steam to use Steamworks, mostly for multiplayer support since Gamespy shut down. Kingdoms is now DLC and the launcher menu has been changed so you can start the campaigns from the launcher. Retail keys should be activatable on Steam.
I couldn't find my key for Kingdoms, but my Medieval 2 vanilla key worked and Kingdoms was included in the DLC list, so I guess it might be free then.
http://forums.totalwar.com/showthread.php/132205
tl;dr
Medieval 2 and Rome have been updated on Steam to use Steamworks, mostly for multiplayer support since Gamespy shut down. Kingdoms is now DLC and the launcher menu has been changed so you can start the campaigns from the launcher. Retail keys should be activatable on Steam.
I couldn't find my key for Kingdoms, but my Medieval 2 vanilla key worked and Kingdoms was included in the DLC list, so I guess it might be free then.