Sometime it is necessary to have an IDP proxy that SPs can all go to. The IDP Proxy will then forward the request to the appropriate IDP.
Non PicketLink Service Providers or .Net applications may need an IDP proxy.
The previous dynamic account chooser functionality implemented is a PicketLink SP feature.
In the simplest form, we may need a simple web app that has configuration to decide the mapping between an IDP and SP.
When a request comes from an SP, the proxy webapp looks at the request and based on its configuration, will redirect to the appropriate IDP.