Winlogon and Gina

I read in the wikipedia about Winlogon, and following links I get to know there's an open source project on a Gina module called pGina. It offers a plugin architecture.

Meanwhile, Vista seems to have killed msgina, and it's offering a complete rewrite towards a new framework to extend a similar architecture to that of pGina, the so called Credential Providers. CPs have the opportunity to provide GUI objects like domain lists, titles, notices, entry fields. The user logon "experience" is visually seamless amongst multiple CPs as the interactive GUI objects are all rendered by Vista's new framework.