The annual Game Developers Conference (GDC), which is being held in San Francisco this week, will get under way shortly with a keynote address from Microsoft's corporate vice president, J Allard, in which he plans to announce some of the key features of the next-generation Xbox. Allard will also comment on Microsoft's vision for the future of entertainment, which he believes will be fueled by demand for video game experiences that are always connected, always personalized, and always in high-definition.

"In the HD Era, the platform is bigger than the processor," reads a quote from Allard in a mistimed press release. "New technology and emerging consumer forces will come together to enable the rock stars of game development to shake up the old establishment and redefine entertainment as we know it."

The big news, of course, is that Allard will use the keynote address to announce key features of Microsoft's successor to the Xbox, which is referred to in the press release only as the "next-generation Xbox." Specifically, Allard plans to release the first details about the next-generation Xbox guide, which is described as a gateway that will instantly connect players to their games, their friends, and their digital media.

Key features of the guide, as described in today's press release, will include:

Gamer Cards: Gamer Cards provide gamers with a quick look at key Xbox Live information. They let players instantly connect with people who have similar skills, interests and lifestyles.

Marketplace: Browsable by game, by genre, and in a number of other ways, the Marketplace will provide a one-stop shop for consumers to acquire episodic content, new game levels, maps, weapons, vehicles, skins and new community-created content.

Micro-transactions: Breaking down barriers of small-ticket online commerce, micro-transactions will allow developers and the gaming community to charge as little as they like for content they create and publish on Marketplace. Imagine players slapping down $.99 to buy a one-of-a-kind, fully tricked-out racing car to be the envy of their buddies.

Custom playlists: This feature eliminates the need for developers to support custom music in games. The guide instantly connects players to their music so they can listen to their own tracks while playing all their favorite next-generation Xbox games.

By supporting features such as custom playlists, friends lists, and voice chat at a chip level, Microsoft hopes to allow developers to focus on creating games rather than on developing for technical certification requirements. The next-generation Xbox hardware is designed around a number of key principles, the following of which are taken straight from today's press release:

A well-balanced system that will deliver more than a teraflop of targeted computing performance.

A multicore processor architecture co-developed with IBM Corp. that provides developer "headroom" and flexibility for the HD Era.

A custom-designed graphics processor co-developed with ATI Technologies Inc. designed for HD Era games and entertainment applications.

In addition, familiar software technologies such as DirectX, PIX, XACT and the recently announced XNA Studio--an integrated team-based development environment tailored for game production--complement the new hardware to help game developers unlock increasingly powerful and complex silicon.

We'll bring you more information on the next-generation Xbox after J Allard's keynote, which, at the time of writing, is scheduled to start in a little under an hour.