A new version of the CredentialsDialog is available. This version adds support for windows 2000 and earlier operating systems that don't support the CredUIPromptForCredentials API. Support is provided by a fully managed "pseudo" dialog which looks similar to native one. Extension panels are still supported, and shouldn't require any knowledge of which dialog they are being hosted in. Saving credentials is also supported through the DPAPI (on windows 2000, on earlier systems this is disabled since the DPAPI is unavailable).
I'm pretty happy with the way the whole project degrades gracefully, using whatever APIs are available. I still want to add support for detecting if we have permissions to call native code and falling back to the fully managed version when we don't. Then the project could be used in untrusted environments as well.
Anyway, I'm off to my handball finals this arvo then on to the Bullets first home game. I've been meaning to go to a game for a few years but haven't got around to it. Finally I'm going thanks to a birthday present from my brother-in-law and his girlfriend. At least I'm moving on after the Lions' loss :(