Microsoft announced Game Stack today, an all-in-one solution for game developers. It combines all of the company's tools and services for game development into one offering. Game Stack includes things like Azure, PlayFab, Xbox Live, Havok, DirectX, Visual Studio, and more.
A big focus here is PlayFab - bought by Microsoft over a year ago - which is being brought into the Azure family. The service provides back-end development services, analytics, and LiveOps, so that will be combined with Azure's "reliability, global scale, and enterprise-level security".
The company made a point of saying that Game Stack is "cloud, network, and device agnostic", so while Azure is a part of it, it should run on any cloud. Moreover, this is about bringing games to any devices. Microsoft cited two billion gamers worldwide, and obviously developers want to reach as many of them as possible, and the vast majority of them aren't playing on an Xbox.
Most gamers, in fact, are playing on their phones, which is why Microsoft opened up Xbox Live to iOS and Android today as well. Mostly, the company says that this is just the beginning, and there's a lot more to come.