Spent some time today hacking on something I have wanted to be able to do from C# for a while, and am now able to do.
You can now implement custom TreeView CellRenderers completely in C#. The code to do so, and a sample Renderer have been checked into gtk-sharp's cvs.
Here is the quick port of some c code I found around for the sample. It needs some work to look real nice, but its pretty cool regardless.
