According to a blog post today by Microsoft's Vice President & Deputy General Counsel Dave Heiner, Google is still blocking the development of a YouTube app for the Windows phone. This move, not a new one on Google's part, prevents "Microsoft from offering consumers a fully featured app for the Windows Phone." While Google has allowed YouTube app development on Android and iOS devices--one of the most downloaded apps on both OS in 2012--they still refuse to do the same for Windows Phone users.
Microsoft is still complaining that this is a clear violation of antitrust laws to both the U.S. Federal Trade Commission and the European Commission. Google has been warned to address the areas of concern or face enforcement action.
Google, on the other hand, states that they are not stopping YouTube access on the Windows phones. Users simply need to use the HTML 5-based mobile website to view videos. Google also said they did not intend to develop additional apps for Microsoft's mobile platform because the small user base.