During the last days I needed to develop a custom Authentication and impersonation mechanism for Indigo. It was not so easy, due to the lack of documentation, since we're still in early betas/ctps. By the way I handled it and here is what I've discoverded, in case someone else is looking for this.
Of course, because I'm just a WCF lover and I'm working with it because I need to use it in a real project of a customer of mine, please if someone (eventually from Indigo team...) has any kind of comment or errata corrige about this post ... please do it, I will really apreciate it. Thanks.