Confirming yesterday's whispers, Microsoft announced that today marks the launch of Comcast Xfinity, HBO Go, and MLB.tv apps for Xbox Live — three new heavy-hitters that join the likes of Netflix, Hulu, YouTube, VEVO, and more. The launches mark a milestone for the Xbox 360 as the company poises to make the home console a versatile media hub not just for gamers. And while some may argue Comcast and HBO apps are served just fine with their cable box — you must subscribe to both services ahead of time to be used on the console — Microsoft is hoping to incentive its apps with media unification across the Xbox ecosystem and use of Kinect voice search. Vox Games has a thorough rundown of MLB.tv for Xbox 360.