Microsoft announced that 400+ pieces of downloadable Xbox Live Marketplace content will be available to 360 users on November 22nd. Premium content will be purchased with Microsoft Points (1,600 Points = $20). Points are sold via Live! and via retail outlets.
Free content appears limited to trailers, demos, and music videos for now. “Premium” content includes “Gamer Pictures” and “Themes” to customize your Live! experience, and downloadable casual and classic games.
Microsoft’s hope, of course, is to encourage purchase of in-game content, like new cars, weapons, etc, not to mention game expansion packs. I hope that publishers put serious thought into using Live! to lower the initial cost of (some) games, thus broadening the market to users who can’t necessarily afford many $50 titles per year, and capturing more value overall when people (who can) voluntarily choose to pay more for extra playtime, features, etc.