System.Web.Providers.Entities.MembershipEntity - how do I use this type with ASP.NET Membership functionality?

How do I use an EntityFramwork 4.0 MembershipProvider as the default for my System.Web.Security.Membership.Provider values?
I like the way the MembershipEntity allows me to get more properties in this type versus the regular System.Web.Security.MembershipUser. How can I use this type, in fact, all of the Entity types in System.Web.Providers.Entities look much more transparent when it comes to sharing properties versus the older MembershipUser type. So I want to migrate to this new method. Is it officially available and how do I go about this?

Edit: If Microsoft doesn't want me using this type why in the hell are they exposing it as a public type? I want some answers.
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