The details are still sketchy, but Microsoft (MSFT) said Monday it plans to offer live television on its Xbox 360 video gaming console.

With the announcement, it's clear that Microsoft is very serious about making its gaming system the entertainment center of the living room. The company also plans to bring YouTube to the console.

I'm not sure how earthshaking the news is. After all, the median age for broadcast audiences has climbed to 50.1 at NBC, 52.3 at ABC, 45.4 at Fox and 56 at CBS. The typical Xbox 360 player seems not to watch a whole lot of live network TV. But still, Microsoft is knocking down another content door for users. (MSN Money is a division of Microsoft.)

The announcement came at Microsoft's press event at the Electronic Entertainment Expo, the annual convention for the video game industry. Microsoft said it will partner with domestic and international broadcasters on live TV but didn't say whom or when or what programs.

We might get a clue about what's coming by looking to the United Kingdom, where Microsoft has offered live TV through a partnership with SkyTv. But SkyTv already has a sophisticated online live TV operation, which it was able to extend through the Xbox 360. Major U.S. networks have very little online live TV presence to speak of, and I imagine Microsoft would have a tough time getting ABC or MTV to commit.

Microsoft would have liked to announce a live TV partner, and the fact that it didn't spoke volumes for the resistance the U.S. broadcast industry is likely fronting here. The more interesting piece of the announcement will come later when the first U.S. partnerships are divulged.

Microsoft is making big promises, saying it will expand its content partnerships tenfold.

At any rate, the Xbox Live service already offers Netflix and Hulu Plus in its library, so the addition of YouTube and some version of live TV says a lot about how Microsoft views its Xbox 360 console. Microsoft wants to go beyond gamers to reach everyone in the house. It wants to be the first stop for people watching "The Office" season finale, the latest wacky YouTube video and the Netflix streaming lineup.

Microsoft's rivals are in similar expansion modes. Nintendo ensured its own spot in living rooms by offering a revolutionary lineup of Wii games that appeal to both genders and every age group. Sony has tried, unsuccessfully at times, to link its PlayStation 3 with its vast content library.

We'll hear a lot more about these efforts this week as the E3 expo continues in Los Angeles. Games used to be the focus of this convention, but the momentum is shifting to online and live video as well.