The "Gaming-On-Demand" service for the XBOX 360, which will start off with 21 exciting games, is set to be here by August 11th (via a dashboard update).
The 21 games are as follows:
Assassin's Creed (Ubisoft)
BioShock (2K Games)
Burnout Paradise (EA)
Call of Duty 2 (Activision)
Dance Dance Revolution Universe (Konami)
Fight Night Round 3 (EA)
Kameo: Elements of Power (Microsoft Game Studios)
Karaoke Revolution American Idol Encore (Konami)
LEGO Star Wars: The Complete Saga (LucasArts)
Mass Effect (Microsoft Game Studios)
Meet The Robinsons (Disney)
MX vs. ATV Untamed (THQ)
Need for Speed Carbon (EA)
Need for Speed: Most Wanted (EA)
Perfect Dark Zero (Microsoft Game Studios)
Prey (2K Games)
Rainbow Six Vegas (Ubisoft)
Ridge Racer 6 (Namco)
Rockstar Games Presents Table Tennis (Rockstar Games)
Sonic the Hedgehog (SEGA)
Test Drive: Unlimited (Atari)
The Elder Scrolls IV: Oblivion (2K Games/Bethesda Softworks)
Viva Piñata (Microsoft Game Studios)
Viva Piñata 2: Trouble in Paradise (Microsoft Game Studios)
Microsoft has been very vague in what each title will cost but, has said it will range between $20 - $30. Your not only paying for the games, you are also paying for the "convenience" factor as well.
What I mean is some games will list for $29.99 to purchase, yet you can go to your local gaming store (ie. GameStop) and buy a physical copy for $19.99. So before you buy the digital version, it may be worth your time to check pricing at your local store(s), as it could definitely be cheaper.