It seems that after opening up the client code some people just cannot await the arrive of the server code under an Opensource license any longer and took matters in their own hands right now.
Enter: Opensim. This is first project that I know of trying to reimplement the server side parts of SL, written in C#, using libsecondlife. So far they claim that you can login, object creation, movement, object updates and chat are working. It started at the end of January and is considered pre alpha.
But – who cares. It has started and now I am curious to see where this project goes and how far it is going to evolve.
So, if LL never opens up the server, people could aid this project and well – who cares, then, if they make it right and get it going.