Hi Marco,
Glad to hear that Cassia has been useful to you!
Yes, the project is more or less in stasis at this point - I no longer work much with Remote Desktop Services, and don't have easy access to test environments for trying out new features. That said, Cassia already supports most of the underlying RDS API, which is very stable and hasn't changed that much since the Windows 2000 days.
There is also the
RemoteDesktop PowerShell module, which is particularly useful for configuring RDS deployments. You can invoke cmdlets from .NET code, though the syntax for that left a bit to be desired last time I tried it.
If I were starting a new project that focused on configuration and deployment of RDS environments, I'd go for the PowerShell module; if the focus was on monitoring or managing sessions on RDS servers, Cassia would probably still be my first choice.
Dan