Since 2010, Microsoft has been using the fictional Contoso Corporation to illustrate best practice, to showcase technology and as subject matter for training material and tests. Recently a new poster describing the company's IT infrastructure has been released on the TechNet library Cloud IT architecture resources.
The poster illustrates how the company has adopted Microsoft's cloud offerings in Networking, Identity, Security and Management. The poster, view-able as a PDF, Visio or Word document, provides background on the organization including a summary of the IT infrastructure related to business needs. The requirements are then mapped specific cloud offerings ranging from SaaS to PaaS to IaaS. Though it does not cover implementation, the poster does cover a wide range of concerns ranging from accessibility to security in regards to application and server architecture (e.g., regional and satellite servers).
Another great Azure architecture reference!