Microsoft is getting involved with the European Union's antitrust investigation regarding Google, mostly regarding the lack of information Google provides search engine competitors for indexing YouTube videos. But even more interesting is Microsoft's claim that their app is lacking because Google won't provide the Windows Phone 7 team with the necessary data for the YouTube app that the versions on Android and iOS have.
Second, in 2010 and again more recently, Google blocked Microsoft's new Windows Phones from operating properly with YouTube. Google has enabled its own Android phones to access YouTube so that users can search for video categories, find favourites, see ratings, and so forth in the rich user interfaces offered by those phones. It's done the same thing for the iPhones offered by Apple, which doesn't offer a competing search service.
Unfortunately, Google has refused to allow Microsoft's new Windows Phones to access this YouTube metadata in the same way that Android phones and iPhones do. As a result, Microsoft's YouTube "app" on Windows Phones is basically just a browser displaying YouTube's mobile Web site, without the rich functionality offered on competing phones. Microsoft is ready to release a high quality YouTube app for Windows Phone. We just need permission to access YouTube in the way that other phones already do, permission Google has refused to provide.