When I developed the WCF Membership Provider, I envisioned it being used as the basis for authentication across a wide array of products on any number of platforms. The only requirement that the client application would need to have is that it could speak to web services using SOAP. Out of the box, the code I presented in my article does not directly achieve that goal. More work is necessary to make that a reality.
Specifically, I would implement System.Web.ApplicationServices as the front end of the WCF Membership Provider by adding these services to a web site in the DMZ. Non-ASP.Net clients and external web sites that did not need to have CreateUser/CreateRole/DeleteUser/... functionality would use these services. ApplicationServices implements the subset of functionality required to authenticate against an ASP.Net membership store. The Sql Server membership store that I chose to use is installed into a database in your application's database layer. There's a command line tool that ships with all versions of the .Net framework. I used .Net 4.0 for the code in my article.
Click here for a walk through on how to install SqlMembershipProvider's membership store.
Click here for a walk through on setting up System.Web.ApplicationServices.