Chief marketing officer Yusuf Mehdi announced that the platform will introduce 35 entertainment providers to improve its sports, movies and foreign language offerings.
ESPN is on board to bring its programming to Xbox Live subscribers around the clock. More than 40 NFL games will air each week, and an NBA League Pass will offer more than 2,400 games for a fee.
Movies from Viacom's Paramount studio, shows from Spanish-language broadcaster Univision Communications Inc, and cartoons from Nickelodeon have also been added to the Xbox Live roster, as well as content from Machinima and Univision.
Microsoft has also improved the service's Kinect navigation via Bing Voice Search, which is being rolled out in numerous new territories. Users can now search for media by genre by uttering an audible command.
The company also announced that its Internet Explorer web browser is coming to the Xbox 360, and unveiled the SmartGlass as a means of integrating its content across tablets, smartphones and other connected devices.
Microsoft's Xbox Music streaming service was also outed during the presentation.
> Read our live blog of Microsoft's E3 2012 conference