Apparently, an article was posted that both
Joystiq and
Kotaku picked up on regarding Xbox 1 games being available for download after the December 2nd Console Update. The price is rumored to be $15 each, which is probably more expensive than buying them used (or pulling from your collection). One bit that could offset this would be the inclusion of XBLA sized achievements (possibly at 200 points each) to give the DLC versions some demand. The rumored games are:
Fable,
Indigo Prophecy,
Crimson Skies: High Road to Revenge,
Crash Bandicoot: The Wrath of Cortex,
Burnout 3 and
Halo: Combat Evolved.