Another 3 years gone by... Still the thing holding us up is mono not supporting Windows Identity Foundation.
However, there are exciting things happening in the .NET/Linux world... Native .NET support and coding platforms...
Windows Identity Foundation is being shunned now, in favour of modern technologies like OWIN.
@Georgi - Any likelihood of moving away from WIF? Or better yet - moving up towards vNext? I know we just got ASP.NET 4.5 a second ago, but I'm feeling greedy..
I'd just love to see us able to host sites using anything but IIS. It's got it's good points, but it's sure got some bad ones too!