ASP.NET Web Site + Windows Forms App + WCF Service: Client Credentials

Let’s say that I’m considering designing a WCF service whose primary purpose is to provide broad services that can be used by three disparate applications: a public-facing Web site, an internal Windows Forms application, and a wireless mobile device. The purpose of the service is twofold: (1) to consolidate code related to business processes in a central location and (2) to lock down access to the legacy database, finally and once and for all hiding it behind one suite of services.