The Xbox Live Marketplace will now provide access to "download-to-own TV shows and download-to-rent movies".
Microsoft claims to have sold six million Xbox 360 consoles by the end of September 2006.
Taking a dig at rival Sony, which launched its long-awaited PlayStation 3 last week amid serious supply shortages, Microsoft said that its Xbox 360 is "prepared to have a booming holiday season, with consoles readily available at retail".
"We are exactly where we wanted to be this holiday with Xbox 360 retail stock availability," said Jeff Bell, corporate vice president of global marketing for the Interactive Entertainment Business at Microsoft.
Examples of content available on the Xbox Live network on 22 November include CSI, CSI: Miami, Star Trek, South Park, Pimp My Ride, Invader Zim, Chinatown, Star Trek VII: Generations, Patriot Games, Star Trek II: The Wrath of Khan, The Sum of All Fears and The Untouchables.
Scientists create a virtual reality simulation of a black hole sitting at the centre of the Milky Way
Simulations like this can help people understand complicated systems in the universe in a better way
The most luminous galaxy ever discovered is cannibalising at least three of its smaller neighbours, study finds
The galaxy radiates at 350 trillion times the luminosity of the Sun
Researchers modify genetic code of cancer-killing virus so it can target cells that protect cancer from immune system
Changing the genetic coding causes the infected cancer cells to produce a protein that kills the fibroblast cells that protect cancer
The findings can help improve the current understanding of brain development disorders, such as epilepsy or autism