Just as we expected, Microsoft is getting official with its Windows Media Center Internet TV feature, which is set to go live in beta fashion tomorrow morning. According to Microsoft, US-based users of Vista Home Premium and Vista Ultimate will soon be able to download a simple update that will enable them to "enjoy a range of television and video content on their PCs and TV sets [with a Media Center Extender of some sort] without a TV tuner in their PC." The streaming content will all be ad-supported "by an advertising platform provided by YuMe," which means that you'll be getting it gratis. The programming reportedly "comes from MSN Video," and just over 100 hours of it will be available when the beta begins. To whet your appetite, a few notables that will be available are "full episodes of TV shows such as 'Arrested Development,' full-length music concerts by artists such as Chris Cornell, Snoop Dogg, Elton John, Pink, John Mayer and the Pussycat Dolls, movie trailers, news segments from MSNBC, and sports clips from FOX Sports."